11. Introduction to Acids, Bases, ph, and Buffers

Size: px
Start display at page:

Download "11. Introduction to Acids, Bases, ph, and Buffers"

Transcription

1 11. Introduction to Acids, Bases, ph, and Buffers What you will accomplish in this experiment You ll use an acid-base indicating paper to: Determine the acidity or basicity of some common household substances Compare the ph of two different concentrations of strong acid and strong base solutions Compare the ph of strong and weak acid solutions that have equal concentrations Compare the ph of strong and weak base solutions that have equal concentrations Investigate the impact of adding a strong acid or strong base to a buffer system. Concepts you need to know to be prepared Bronsted-Lowry Acids and Bases In 1923, Johannes Bronsted of Denmark and Thomas Lowry of England independently proposed the same theory about acid and base compounds and the chemical reaction that occurs between them. The Bronsted-Lowry Theory focuses on the movement of the hydrogen ion, H + (which is usually referred to as just a proton ). Bronsted and Lowry define an acid as a compound which can donate a proton. They define a base as a compound that can accept a proton. An acid-base reaction is then simply the transfer of a proton from the acid to the base. Even the simple dissolution of an acid in water results in a Bronsted-Lowry acid-base reaction, because the acid molecule donates a proton to the water molecule. For example, when the molecular compound hydrogen chloride dissolves in water, it dissociates into ions, producing a proton, H +, and a chloride ion, Cl -. The dissociated proton is donated to a water molecule to produce the hydronium ion, H 3 O +. HCl (aq) + H 2 O (l) H 3 O + (aq) + Cl (aq) As the HCl molecule is donating the proton, it is acting as a Bronsted-Lowry acid. For this reason, we refer to solutions of HCl in water as hydrochloric acid. As the H 2 O molecule is accepting the donated proton, it is acting as a Bronsted-Lowry base. C. Graham Brittain Page 1 of 14 11/23/2010

2 According to Bronsted-Lowry theory, every acid-base reaction creates a conjugate acid-base pair. In the acid-base reaction shown below, nitric acid (HNO 3 ) donates a proton (H + ) to a water molecule. The polyatomic nitrate ion (NO 3 - ) is said to be the conjugate base of nitric acid. Similarly, the hydronium ion, (H 3 O + ) is called the conjugate acid of the H 2 O molecule. Thus HNO 3 and NO 3 - are a conjugate acid-base pair; H 2 O and H 3 O + are also a conjugate acid-base pair. Strong and Weak Acids This idea of conjugate acid-base pairs raises an interesting question: If the hydronium ion (H 3 O + ) is truly an acid, and can donate a proton to the nitrate ion base (NO 3 - ), why doesn t the above reaction reverse itself? Why don t hydronium ions (H 3 O + ) donate their protons (H + ) back to the nitrate ions (NO 3 - ) to re-form the HNO 3 and H 2 O molecules? The answer is that not all acids have the same proton-donating capabilities, and not all bases are equal in their proton-accepting capabilities. Acids that are particularly good proton donors (dissociating nearly 100% to produce large amounts of hydronium ion) are said to be strong acids. Conversely, good proton acceptors (generating large amounts of hydroxide ion) are called strong bases. In the above reaction, HNO 3 is such an exceptionally strong acid that the dissociation (ionization) reaction of hydrogen chloride with water goes essentially to completion. And as the hydronium ion, H 3 O +, is a comparatively weak acid (and the NO 3 -, is an extremely weak base: a miserably poor proton acceptor), the above reaction has no tendency at all to reverse itself. The number of acids that are considered to be strong is actually quite small; your lecture textbook lists just a few strong acids: Hydrochloric acid (HCl) Hydrobromic acid (HBr) Nitric Acid (HNO 3 ) Sulfuric Acid (H 2 SO 4 ) All other acids are considered to be weak, in that they vary considerably in the extent to which they dissociate in water (donate their protons to water molecules) to produce the hydronium ion, H 3 O +. Because the dissociation of weak acids is an equilibrium process, we can use equilibrium constants to tell us quantitatively just how strong any weak acid is; that is, how readily the weak acid donates its proton to water. An equilibrium constant describes the position of the equilibrium by expressing the concentrations of the products and reactants that are present in solution as a ratio: = The brackets [ ] mean concentration of, and the unit used to express the concentration is always molarity (moles of solute per liter of solution, or moles/l, M). C. Graham Brittain Page 2 of 14 11/23/2010

3 The dissociation of ANY weak acid (HA) in water can be represented as: HA (aq) + H 2 O (l) H 3 O + (aq) + A - (aq) And the equilibrium constant expression (K) for the dissociation of ANY weak acid can be written as: = As this equilibrium constant describes the extent of dissociation of a weak acid in water, it s known as the Acid Dissociation Constant, K a. The K a values of several weak acids are shown below. The Amphiprotic Water Molecule: Self-Ionization of Water Water molecules are remarkable in that they can undergo self-ionization: One water molecule acts as an acid and donates a proton; A second water molecule behaves as a base and accepts the proton. The products of this Bronsted-Lowry acid-base reaction are the hydroxide ion, OH -, and the hydronium ion, H 3 O +. A compound that can act as either an acid or a base is said to be amphiprotic. H 2 O (l) + H 2 O (l) H 3 O + (aq) + OH - (aq) The above reaction occurs in pure water to only a very small equilibrium extent, that is, very few hydroxide and hydronium ions are formed. When the self-ionization reaction reaches equilibrium (and the rates of the forward and reverse reaction are equal), only 1.0 x 10-7 moles of hydroxide ion and 1.0 x 10-7 moles of hydronium ion can be found in one liter of water. C. Graham Brittain Page 3 of 14 11/23/2010

4 These concentrations can be expressed mathematically as follows: [H 3 O + ] = [OH ] = 1.0 x 10 7 M (moles/liter) And the extent of the equilibrium can be described by writing an equilibrium constant expression called the Ion Product of Water, K w : = = = The value of the ion product of water applies not only to pure water, but also to any aqueous solution. This is very convenient, because if we know the concentration of ONE of these two ions, we can calculate the concentration of the OTHER. For example, if a solution of hydrochloric acid has a concentration of M (0.010 moles of HCl per liter), the hydronium ion concentration [H 3 O + ] = M = 1.0 x 10-2 M (because the strong acid HCl dissociates completely to produce the hydronium and chloride ions). From the ion product of water, the hydroxide ion concentration [OH ] in this HCl solution can be calculated as: = = = As you can see from this example, the HCl solution has a higher concentration of hydronium ions than does pure water (1.0 x 10-2 M in HCl, only 1.0 x 10 7 M in water), and a lower concentration of hydroxide ions than does pure water (1.0 x M in HCl, but 1.0 x 10 7 M in water). The concentrations of hydronium and hydroxide ions in any aqueous solution are always related such that the product of their concentrations is equal to the value 1.0 x (K w, the Ion Product of Water). The ph Scale Soren P. L. Sorenson introduced the ph scale in the early 1900s as a simplified way of expressing the concentration of hydronium ions in an aqueous acid or base solution. The ph of a solution is defined as the negative logarithm of the hydronium ion concentration: = You should recall that in pure water, the hydronium ion concentration is 1.0 x 10 7 M. The logarithm of this concentration is -7 (the value of the exponent), thus the ph of pure water is equal to 7 (the negative of the exponent s value). Because water is amphiprotic (can act as either an acid or a base), and the concentrations of the hydronium and hydroxide ions are equal in pure water, ph 7 is defined as a neutral solution. The M of the hydrochloric acid solution has a hydronium ion concentration equal to the molarity of the strong acid: [H 3 O + ] = M = 1.0 x 10-2 M (because the strong acid dissociates 100%). The logarithm of this value is -2, so the ph of this HCl solution is equal to 2. On the ph scale, acidic solutions are those that have a ph less than 7. This is because acids donate protons to water, causing the concentration of H 3 O + to become greater than that in pure water (greater than 1.0 x 10 7 M, so a less negative exponent), and thus the ph of the solution decreases from the neutral value of 7 to a smaller number. Basic solutions are those that have a ph greater than 7. This is because bases either release hydroxide ions (OH - ) as they dissolve in water, or bases accept protons from water molecules to create hydroxide ions. In either case, because the concentrations of the hydroxide and hydronium ions are always related by the ion product of water (K w = [H 3 O + ] [OH ] = 1.0 x ), as the concentration of the OH - ion increases (becomes greater than that in pure water), the concentration of H 3 O + ion decreases (becomes less than 1.0 x 10 7 M, a more negative exponent). Thus the ph of the basic solution increases from the neutral value of 7 to a larger number. C. Graham Brittain Page 4 of 14 11/23/2010

5 Strong and Weak Bases Two examples of bases are presented below, and like acids, they are commonly classified as strong or weak, depending on their ability to generate hydroxide ions. Strong bases are typically ionic compounds composed of a hydroxide ion, OH -, and a Group I Alkali Metal ion (such as sodium or potassium). These salts are extremely water soluble, thus they dissociate completely to produce a solution of hydroxide ions. NaOH (s) H 2 O Na + (aq) + OH - (aq) Weak bases can include less water-soluble hydroxide salts, such as Ca(OH) 2, or molecular compounds such as NH 3. The molecular compounds act as classic Bronsted-Lowry bases in that they accept a proton from a water molecule to yield aqueous hydroxide ions. This reaction is reversible, and usually occurs to only a small equilibrium extent. NH 3 (aq) + H 2 O (l) NH 4 + (aq) + OH - (aq) The dissociation of ANY weak base (B) in water can be represented as: B (aq) + H 2 O (l) OH - (aq) + HB + (aq) And the equilibrium constant expression (K) for the dissociation of ANY weak base can be written as: = As this equilibrium constant describes the extent of dissociation of a weak acid in water, it s known as the Base Ionization Constant, K b. The K b values of several weak bases are shown below. C. Graham Brittain Page 5 of 14 11/23/2010

6 The ph of Commonly-Occurring Acid and Base Substances Many common substances are either acids or bases. Citrus fruits such as oranges and lemons contain acid compounds. Vinegar contains acetic acid, HC 2 H 3 O 2. This molecular compound is classified as a weak acid because when dissolved in water, only a small fraction of the acetic acid molecules dissociate and donate their protons to water molecules to make hydronium ions and the conjugate base of acetic acid, the acetate polyatomic ion, C 2 H 3 O 2 -. HC 2 H 3 O 2 (aq) + H 2 O (l) H 3 O + (aq) + C 2 H 3 O 2 - (aq) Bases can be found in antacid preparations and in many household cleaning solutions. The schematic below indicates the ph of a number of familiar aqueous solutions. Realize that if you know the ph of a solution, you can calculate the hydronium ion concentration from the definition of ph: If ph = log [H 3 O + ], then [H 3 O + ] = 10 ph (To use your calculator to find a ph, simply enter the hydronium ion concentration, [H 3 O + ], then press the log button, and then the +/- or (-) button. To do the reverse, that is, find a hydronium ion concentration from a ph, simply enter the ph value, press the +/- or (-) button, and then the anti-log or 10 x button.) Thus if the ph of blood is normally between 7.35 and 7.45, then the hydronium ion concentration in blood is normally between 3.55 x 10-8 and 4.47 x 10-8 M (moles H 3 O + /liter blood solution): If ph = 7.35 = log [H 3 O + ], then [H 3 O + ] = 10 ph = = 4.47 x 10 8 M And if ph = 7.45 = log [H 3 O + ], then [H 3 O + ] = 10 ph = = 3.55 x 10 8 M C. Graham Brittain Page 6 of 14 11/23/2010

7 The Buffering Capability of Weak Acids and their Conjugate Bases Solutions of weak acids and their conjugate bases are extremely useful in everyday life because of their ability to resist changes in ph. Another way to say this is that they have buffering capability, or that they can serve as buffers of the ph of an aqueous solution. A buffer is a solution that contains two solutes: a weak acid, and the conjugate base of that weak acid. These solutes are present in equal (or approximately equal) concentrations. (Remember that the conjugate base is the polyatomic anion that is produced when a weak acid dissociates in water.) For example, a buffer could be made of acetic acid, HC 2 H 3 O 2, and its conjugate base, the acetate ion, C 2 H 3 O 2 -. HC 2 H 3 O 2 (aq) + H 2 O (l) H 3 O + (aq) + C 2 H 3 O 2 - (aq) If we attempt to change the ph of a buffered solution by adding a strong acid (to lower the ph) or by adding a strong base (to raise the ph), the buffer is able to resist the ph change. This is because the buffer contains a weak base that is capable of reacting with any added acid, and it contains a weak acid that can react with any added base. For example, if hydrochloric acid, HCl, is added to an acetic acid/acetate buffer, the C 2 H 3 O 2 - ion (as the conjugate base) can react with the HCl, preventing it from increasing the hydronium ion concentration and lowering the ph of the solution: C 2 H 3 O 2 - (aq) + HCl (aq) HC 2 H 3 O 2 (aq) + Cl - (aq) Some of the C 2 H 3 O 2 - ion is converted to HC 2 H 3 O 2 by this reaction; thus, the concentration of the C 2 H 3 O 2 - ion will decrease with the addition of HCl, and the concentration of acetic acid will increase. But note that the ph of the buffer solution will remain relatively constant (since the concentrations of H 3 O + and OH remain relatively constant). The impact of an added strong base can also be minimized by this buffer solution. For example, sodium hydroxide, NaOH, will react with the HC 2 H 3 O 2 in the buffer (converting it to C 2 H 3 O 2 - ion), rather than increasing the hydroxide ion concentration in the solution and raising the ph. HC 2 H 3 O 2 (aq) + NaOH (aq) Na + (aq) + C 2 H 3 O 2 - (aq) + H 2 O (aq) The above reactions will occur and maintain the ph of the solution as long as there are enough acetate ions (C 2 H 3 O 2 - ) to react with any added acid, or enough acetic acid molecules (HC 2 H 3 O 2 ) to react with any added base. If either the weak acid or conjugate base is completely used up in these reactions, then the buffer s capacity has been exceeded, and any additional acid or base will cause the ph to change. Thus the higher the concentrations of the weak acid and conjugate base in the buffer system, the greater the buffer capacity, and the more moles of strong acid or base that can be added to the buffer without causing a significant change in ph. Buffers are critically important in biological situations. The human body uses a variety of buffering systems to maintain both extracellular and intracellular solutions at the optimal ph. For example, the carbonic acid bicarbonate ion buffering system (H 2 CO 3 HCO 3 - ) is critical to maintaining the ph of the blood between 7.35 and C. Graham Brittain Page 7 of 14 11/23/2010

8 Indicators of ph An acid-base indicator is a molecular compound that undergoes a color change when the ph of the solution containing the indicator reaches a certain value. Some common indicator compounds are listed in the figure below. You ll note that the different indicators change color at different ph ranges; this allows chemists to select a specific indicator that will change color at precisely the desired ph. Indicator solutions can be added directly to solutions of acids or bases. Alternatively, strips of filter paper can be impregnated with indicator compounds to produce ph paper. When a drop of acid or base solution is touched to the ph paper, the paper will change colors. By matching the color of the paper to an indicator color chart, the ph of the solution can be determined. In today s experiment, you ll use an acid-base indicating paper to: Determine the acidity or basicity of some common household substances Compare the ph of two different concentrations of strong acid and strong base solutions Compare the ph of strong and weak acid solutions that have equal concentrations Compare the ph of strong and weak base solutions that have equal concentrations Investigate the impact of adding a strong acid or strong base to a buffer system. phydrion Acid-Base Indicating Paper The acid-base indicating paper you ll use in this experiment ph impregnated with a universal indicator solution that is able to turn one of fourteen different colors in response to ph values from 0 (extremely acidic) to 13 (extremely basic). As the ph of tested solutions vary from acidic to basic, the response colors of the phydrion range from red (ph = 0) to orange to yellow to light green (ph = 7) to dark green to light blue to dark blue (ph = 13). The various hues are too complex to describe here, so the test strips of the ph paper must be compared with a phydrion color chart. C. Graham Brittain Page 8 of 14 11/23/2010

9 Procedure that you will follow A. ph of Common Household Substances 1. Examine the clear plastic well plate in your laboratory equipment drawer. It should be of one of two designs: Three rows (labeled A, B, C) containing four wells (labeled 1, 2, 3, 4) in each row, OR Four rows (labeled A, B, C, D) containing six wells (labeled 1, 2,3, 4, 5, 6) in each row. 2. You ll obtain a sample of each of the nine common household substances listed below (and in the Data/Results table in the Report Sheet) in a separate well in the well plate. To keep from confusing the samples with one another, as you add each sample to a well, record the label of that well (ex: A-1 for row A, well #1) on the Report Sheet. The substances are: Carbonated Soda White Vinegar Lemon Juice Distilled Water Sodium Chloride Table Sugar (Sucrose) Sodium Bicarbonate Antacid Tablet Household Ammonia 3. Obtain the samples as follows: For liquids: Use a pipet or eye-dropper to add 10 drops of the solution to the well. For solids: Use a spatula to place a sample about the size of a match head into the well (some solids may need to be crushed). Add 10 drops of distilled water to the sample in the well and stir to dissolve. 4. Test for the actual ph value of each sample with phydrion paper by touching a glass stirring rod to the solution, then touching the rod to the paper (be sure to wipe the rod clean between samples). In this way, the same piece of phydrion paper can be used to test several different samples. Use the color chart provided with the phydrion paper to determine the actual ph. Note: The color change of the ph paper must be observed while the paper is still wet with the tested solution. 5. Dispose of the samples by rinsing the contents of the well plate into a large waste beaker, then pouring this into the appropriate waste container. B. Determining the ph of Strong and Weak Acids and Bases 1. Place a 1 ml sample of each the following acid or base solutions in a separate well in the well plate. Again, to keep from confusing the solutions with one another, as you place each sample in a well, record the label of that well (ex: A-1 for row A, well #1) on the Report Sheet. The solutions are: 0.10 M HCl (hydrochloric acid, a strong acid) M HCl (hydrochloric acid, a strong acid) 0.10 M NaOH (sodium hydroxide, a strong base) M NaOH (sodium hydroxide, a strong base) 0.10 M HC 2 H 3 O 2 (acetic acid, a weak acid) 0.10 M NaC 2 H 3 O 2 (sodium acetate, a weak base) C. Graham Brittain Page 9 of 14 11/23/2010

10 0.10 M NH 3 (ammonia, a weak base) 0.10 M NH 4 Cl (ammonium chloride, a weak acid) 2. Test for the actual ph value of each solution with phydrion paper. As before, use the glass stirring rod to test several different samples on the same piece of ph paper. Use the color chart provided with the container of phydrion paper to determine the actual ph. 3. Dispose of the samples by rinsing the contents of the well plate into a large waste beaker, then pouring this into the appropriate waste container. C. Determining the Effect of a Buffer 1. Place the samples listed below into separate wells in the well plate as indicated by the labels below. Buffer in well A-1 (Acetic Acid/Acetate): 1 ml of 0.10 M HC 2 H 3 O 2 and 1 ml of 0.10 M NaC 2 H 3 O 2 Buffer in well A-2 (Acetic Acid/Acetate): 1 ml of 0.10 M HC 2 H 3 O 2 and 1 ml of 0.10 M NaC 2 H 3 O 2 Buffer in well B-1 (Ammonium/Ammonia): 1 ml of 0.10 M NH 4 Cl and 1 ml of 0.10 M NH 3 Buffer in well B-2 (Ammonium/Ammonia): 1 ml of 0.10 M NH 4 Cl and 1 ml of 0.10 M NH 3 Control in well C-1: 2 ml of distilled water Control in well C-2: 2 ml of distilled water 2. Test for the actual ph value of each buffer solution (and the control samples) with phydrion paper. As before, use the glass stirring rod to test several different samples on the same piece of ph paper. Use the color chart provided with the container of phydrion paper to determine the actual ph. 3. To the samples in wells A-1, B-1, and C-1: Add 1 drop of the 0.10 M HCl solution. Mix the samples carefully by gently swirling the well plate. Test for the actual ph of each sample with phydrion paper (using the glass stirring rod to test the three samples on the same piece of ph paper, and comparing the colors with the chart to determine the actual ph). 4. To the samples in wells A-2, B-2, and C-2: Add 1 drop of the 0.10 M NaOH solution. Mix the samples carefully by gently swirling the well plate. Test for the actual ph of each sample with phydrion paper (using the glass stirring rod to test the three samples on the same piece of ph paper, and comparing the colors with the chart to determine the actual ph). 5. Dispose of the samples by rinsing the contents of the well plate into a large waste beaker, then pouring this into the appropriate waste container. C. Graham Brittain Page 10 of 14 11/23/2010

11 Report Sheet 10: Introduction to Acids, Bases, ph, and Buffers Student Lab Partner Date Lab Performed Section # Lab Instructor Date Report Received Lab Notebook: Data and Observations A. Determining the ph of Common Substances For each one of the common substances tested: Were the ph results you obtained (relative acidity or basicity) consistent with what you would expect for that substance? Did you expect the substance to be an acid? A base? Did you expect the ph to be that high? That low? Explain how the results compared to your expectations for each substance Substance Spot Plate Code Color phydrion Paper phydrion ph Explain how results compare to expectations Carbonated Soda White Vinegar Lemon Juice Distilled water Sodium Chloride Sugar (sucrose) Sodium Bicarbonate Antacid Tablet Household Ammonia C. Graham Brittain Page 11 of 14 11/23/2010

12 B. Determining the ph of Strong and Weak Acids and Bases Solution Spot Plate Code Known to be acid or base? Known to be weak or strong? Color phydrion Paper phydrion ph 0.10 M HCl M HCl 0.10 M NaOH M NaOH 0.10 M HC 2 H 3 O M NaC 2 H 3 O M NH M NH 4 Cl C. Determining the Effect of a Buffer BEFORE addition of HCl or NaOH AFTER addition of HCl or NaOH Buffer Solution Spot Plate Code Color phydrion Paper phydrion ph Color phydrion Paper phydrion ph Change in ph ph final ph initial 0.10 M HC 2 H 3 O M NaC 2 H 3 O 2 A M HC 2 H 3 O M NaC 2 H 3 O M NH 4 Cl M NH M NH 4 Cl M NH 3 A-2 B-1 B-2 Distilled water C-1 Distilled water C-2 C. Graham Brittain Page 12 of 14 11/23/2010

13 Formal Report: Results and Conclusions for Effect of Concentration 1. Compare the ph of the two different concentrations of the strong acid HCl: What is the [H 3 O + ] in the 0.10 M HCl solution? And what should theoretically be the ph of the 0.10 M HCl solution? Show your work. What was the measured ph of the 0.10 M HCl solution? What is the [H 3 O + ] in the M HCl solution? And what should theoretically be the ph of the M HCl solution? Show your work. What was the measured ph of the M HCl solution? 2. Compare the ph of the two different concentrations of the strong base NaOH: What is the [H 3 O + ] in the 0.10 M NaOH solution? Show your work. And what should theoretically be the ph of the 0.10 M NaOH solution? Show your work. What was the measured ph of the 0.10 M NaOH solution? What is the [H 3 O + ] in the M NaOH solution? Show your work. And what should theoretically be the ph of the M NaOH solution? Show your work. What was the measured ph of the M NaOH solution? 3. What relationship did you observe between the concentration of the strong acid and the ph of that solution? Between the concentration of the strong base and the ph of that solution? C. Graham Brittain Page 13 of 14 11/23/2010

14 4. List and then compare the measured ph values of the three 0.10 M acid solutions: hydrochloric acid (HCl) acetic acid (HC 2 H 3 O 2 ) ammonium chloride (NH 4 Cl) These three solutions have the SAME concentration, but do they have the SAME ph? You already know that HCl is a strong acid. Of the remaining two acids (both of which are weak acids): Which weak acid has the higher concentration of hydronium ions? Which weak acid is stronger than the other? Which weak acid would have the larger K a value (acid dissociation constant)? Briefly state how you reached these conclusions. 5. List and then compare the measured ph values of the three 0.10 M base solutions: sodium hydroxide (NaOH) sodium acetate (NaC 2 H 3 O 2 ) ammonia (NH 3 ) These three solutions have the SAME concentration, but do they have the SAME ph? You already know that NaOH is a strong base. Of the remaining two bases (both of which are weak bases): Which weak base has the higher concentration of hydroxide ions? Which weak base is stronger than the other? Which weak base would have the larger K b value (base ionization constant)? Briefly state how you reached these conclusions. 6. List and then compare the change in ph when HCl or NaOH was added to each solution below: acetic acid (HC 2 H 3 O 2 ) + sodium acetate (NaC 2 H 3 O 2 ): ph with HCl = ph with NaOH = ammonium chloride (NH 4 Cl) + ammonia (NH 3 ): ph with HCl = ph with NaOH = distilled water: ph with HCl = ph with NaOH = Are these results appropriate for the addition of HCl/NaOH to a buffer solution (vs. pure water)? Explain. C. Graham Brittain Page 14 of 14 11/23/2010

Chem 2115 Experiment #10. Acids, Bases, Salts, and Buffers

Chem 2115 Experiment #10. Acids, Bases, Salts, and Buffers Chem 2115 Experiment #10 Acids, Bases, Salts, and Buffers OBJECTIVE: The goal of this series of experiments is to investigate the characteristics of acidic and basic solutions. We will explore the neutralization

More information

EXPERIMENT 11 Acids, Bases, and ph

EXPERIMENT 11 Acids, Bases, and ph EXPERIMENT 11 Acids, Bases, and ph INTRODUCTION The concept of acidity and alkalinity dates from ancient times. The word acid is derived from the Latin word acidus, meaning sour. A common acid, acetic

More information

What are Acids and Bases? What are some common acids you know? What are some common bases you know? Where is it common to hear about ph balanced

What are Acids and Bases? What are some common acids you know? What are some common bases you know? Where is it common to hear about ph balanced What are Acids and Bases? What are some common acids you know? What are some common bases you know? Where is it common to hear about ph balanced materials? Historically, classified by their observable

More information

What is an acid? What is a base?

What is an acid? What is a base? What is an acid? What is a base? Properties of an acid Sour taste Turns litmus paper red Conducts electric current Some acids are strong and some are weak Properties of a base Bitter taste Slippery to

More information

Chapter 10. Acids, Bases, and Salts

Chapter 10. Acids, Bases, and Salts Chapter 10 Acids, Bases, and Salts Topics we ll be looking at in this chapter Arrhenius theory of acids and bases Bronsted-Lowry acid-base theory Mono-, di- and tri-protic acids Strengths of acids and

More information

Notes: Acids and Bases

Notes: Acids and Bases Name Chemistry Pre-AP Notes: Acids and Bases Period I. Describing Acids and Bases A. Properties of Acids taste ph 7 Acids change color of an (e.g. blue litmus paper turns in the presence of an acid) React

More information

1 Chapter 19 Acids, Bases, and Salts

1 Chapter 19 Acids, Bases, and Salts 1 Chapter 19 Acids, Bases, and Salts ACID-BASE THEORIES Acids and bases are all around us and part of our everyday life (ex. bodily functions, vinegar, carbonated drinks, citrus fruits, car batteries,

More information

What is an acid? What is a base?

What is an acid? What is a base? What is an acid? What is a base? Properties of an acid Sour taste Turns litmus paper red Conducts electric current Some acids are strong and some are weak Properties of a base Bitter taste Slippery to

More information

#12. Acids and Bases.

#12. Acids and Bases. #12. Acids and Bases. Goals: To determine the ph of common substances and observe buffer behavior. Background Acids and bases are very common in chemistry and biology. Understanding acids and bases is

More information

Experiment Eight Acids and Bases

Experiment Eight Acids and Bases Name: Lab Section: Experiment Eight Acids and Bases Objective Identifying and understanding the nature of acids and bases is an important part of the laboratory toolbox, the purpose of this lab is to help

More information

Acids and bases, as we use them in the lab, are usually aqueous solutions. Ex: when we talk about hydrochloric acid, it is actually hydrogen chloride

Acids and bases, as we use them in the lab, are usually aqueous solutions. Ex: when we talk about hydrochloric acid, it is actually hydrogen chloride Acids and Bases Acids and bases, as we use them in the lab, are usually aqueous solutions. Ex: when we talk about hydrochloric acid, it is actually hydrogen chloride gas dissolved in water HCl (aq) Concentrated

More information

Experiment Nine Acids and Bases

Experiment Nine Acids and Bases Name: Lab Section: Experiment Nine Acids and Bases Objective Identifying and understanding the nature of acids and bases is an important part of the laboratory toolbox, the purpose of this lab is to help

More information

Unit 9: Acids, Bases, & Salts

Unit 9: Acids, Bases, & Salts STUDENT VERSION Unit 9: Acids, Bases, & Salts Unit Vocabulary: Arrhenius acid Arrhenius base Bronsted-Lowry acid Bronsted-Lowry base Electrolyte hydronium ion hydroxide ion indicator (acid/base) neutralization

More information

10.1 Acids and Bases in Aqueous Solution

10.1 Acids and Bases in Aqueous Solution 10.1 Acids and Bases in Aqueous Solution Arrhenius Definition of Acids and Bases An acid is a substance that gives hydrogen ions, H +, when dissolved in water. In fact, H + reacts with water and produces

More information

Unit 10: Acids and Bases

Unit 10: Acids and Bases Unit 10: Acids and Bases PROPERTIES OF ACIDS & BASES Properties of an Acid: a Tastes sour substance which dissociates (ionizes, breaks apart in solution) in water to form hydrogen ions Turns blue litmus

More information

10/16/17 ACIDS AND BASES, DEFINED WATER IS AMPHOTERIC OUTLINE. 9.1 Properties of Acids and Bases. 9.2 ph. 9.3 Buffers

10/16/17 ACIDS AND BASES, DEFINED WATER IS AMPHOTERIC OUTLINE. 9.1 Properties of Acids and Bases. 9.2 ph. 9.3 Buffers ACIDS AND BASES, DEFINED A hydrogen atom contains a proton and an electron, thus a hydrogen ion (H + ) is a proton: Acids: Proton (H + ) transfer between molecules is the basis of acid/base chemistry Ø

More information

Toxins 4/27/2010. Acids and Bases Lab. IV-17 to IV-22

Toxins 4/27/2010. Acids and Bases Lab. IV-17 to IV-22 Toxins IV-17 to IV-22 Countless products are advertised on TV with the promise of reducing acid indigestion. a.what is acid indigestion? b.what does acid have to do with your stomach? c.how do you think

More information

What is an acid? What is a base?

What is an acid? What is a base? What is an acid? What is a base? Properties of an acid Sour taste Turns litmus paper red Conducts electric current Some acids are strong and some are weak Properties of a base Bitter taste Slippery to

More information

INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Seventh Edition by Charles H. Corwin

INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Seventh Edition by Charles H. Corwin Lecture INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Seventh Edition by Charles H. Corwin Acids and Bases Properties of Acids An acid is any substance that releases hydrogen ions, H +, into water.

More information

5 Weak Acids, Bases and their Salts

5 Weak Acids, Bases and their Salts 5 Weak Acids, Bases and their Salts Name: Date: Section: Objectives You will be able to define an acid and a base with the Arrhenius and Brǿnsted-Lowry definitions You will be able to predict the behavior

More information

The Chemistry of Acids and Bases

The Chemistry of Acids and Bases The Chemistry of Acids and Bases 1 Acid and Bases 2 Acid and Bases 3 Acid and Bases 4 Acids 5 Have a sour taste. Vinegar is a solution of acetic acid. Citrus fruits contain citric acid. React with certain

More information

The Chemistry of Acids and Bases

The Chemistry of Acids and Bases The Chemistry of Acids and Bases 1 Acid and Bases 4 Acid and Bases 2 Acids Have a sour taste. Vinegar is a solution of acetic acid. Citrus fruits contain citric acid. React with certain metals to produce

More information

Introduction to Acids & Bases. Packet #26

Introduction to Acids & Bases. Packet #26 Introduction to Acids & Bases Packet #26 Review I Svante Arrhenius was the first person to recognize the essential nature of acids and bases. Review II Arrhenius postulated that: Acids produce hydrogen

More information

UNIT 14 - Acids & Bases

UNIT 14 - Acids & Bases COMMON ACIDS NOTES lactic sour milk, sore muscles acetic vinegar phosphoric soft drinks citric citrus fruits malic apples PROPERTIES OF ACIDS PROPERTIES OF BASES 1. Taste sour 1. Taste bitter 2. react

More information

HA(s) + H 2 O(l) = H 3 O + (aq) + A (aq) b) NH 3 (g) + H 2 O(l) = NH 4 + (aq) + OH (aq) Acid no. H + type base no. OH type

HA(s) + H 2 O(l) = H 3 O + (aq) + A (aq) b) NH 3 (g) + H 2 O(l) = NH 4 + (aq) + OH (aq) Acid no. H + type base no. OH type You are already familiar with some acid and base chemistry. According to the Arrhenius model, acids are substances that when dissolved in water ionize to yield hydrogen ion (H + ) and a negative ion. e.g.

More information

Examples of Strong Acids: Strong Acid Formula Common Source Hydrochloric Acid HCl Stomach Acid

Examples of Strong Acids: Strong Acid Formula Common Source Hydrochloric Acid HCl Stomach Acid ACIDS AND BASES: PH AND BUFFERS PURPOSE: To determine the ph of common acids and bases using a ph meter, ph paper, and red cabbage indicator. To test the effect of adding an acid or base to a buffer solution.

More information

Acids, Bases and ph Chapter 19

Acids, Bases and ph Chapter 19 Acids, Bases and ph Chapter 19 Compounds That Become Acids When Dissolved in Water General Formula: HX H + X - monatomic or polyatomic anion Naming Acids (p. 250) Binary acids Hydro ic Acid HCl: Hydrochloric

More information

CHM112 Lab Hydrolysis and Buffers Grading Rubric

CHM112 Lab Hydrolysis and Buffers Grading Rubric Name Team Name CHM112 Lab Hydrolysis and Buffers Grading Rubric Criteria Points possible Points earned Lab Performance Printed lab handout and rubric was brought to lab 3 Initial calculations completed

More information

Molecular Definitions of Acids and Bases: H 2 O (l)

Molecular Definitions of Acids and Bases: H 2 O (l) Molecular Definitions of Acids and Bases: Arrhenius Definition: An acid produces hydrogen ions (H + ) in an aqueous solution. For example: Consider hydrochloric acid, HCl, which when dissolved in water

More information

Mixtures of Acids and Bases

Mixtures of Acids and Bases Mixtures of Acids and Bases PURPOSE To investigate the resulting ph s of different mixtures of acid and base solutions. GOALS To calculate the ph of pure acid and base solutions. To calculate the ph of

More information

To measure ph s in a variety of solutions and mixtures and to account for the results obtained.

To measure ph s in a variety of solutions and mixtures and to account for the results obtained. Acid-Base Studies PURPOSE To measure ph s in a variety of solutions and mixtures and to account for the results obtained. GOALS 1 To learn to use ph paper and a ph meter to measure the ph of a given solution.

More information

Section 32 Acids and Bases. Copyright (c) 2011 by Michael A. Janusa, PhD. All rights reserved.

Section 32 Acids and Bases. Copyright (c) 2011 by Michael A. Janusa, PhD. All rights reserved. Section 32 Acids and Bases 1 Copyright (c) 2011 by Michael A. Janusa, PhD. All rights reserved. Acid-Base Concepts Acids and bases are among the most familiar and important of all chemical compounds. You

More information

Chapter 9: Acids, Bases, and Salts

Chapter 9: Acids, Bases, and Salts Chapter 9: Acids, Bases, and Salts 1 ARRHENIUS ACID An Arrhenius acid is any substance that provides hydrogen ions, H +, when dissolved in water. ARRHENIUS BASE An Arrhenius base is any substance that

More information

Name. Academic Chemistry. Acid Base. Notes. Unit #14 Test Date: cincochem.pbworks.com

Name. Academic Chemistry. Acid Base. Notes. Unit #14 Test Date: cincochem.pbworks.com Periodic Table Name Academic Chemistry Acids & Bases Notes Unit #14 Test Date: 20 cincochem.pbworks.com Acid Base cincochem.pbworks.com Notes Find ph To go from [H 3 O + ] to ph EXAMPLE: [H 3 O + ] = 3.23

More information

ACID BASE EQUILIBRIUM

ACID BASE EQUILIBRIUM ACID BASE EQUILIBRIUM Part one: Acid/Base Theories Learning Goals: to identify acids and bases and their conjugates according to Arrhenius and Bronstead Lowry Theories. to be able to identify amphoteric

More information

Acids and Bases. Properties, Reactions, ph, and Titration

Acids and Bases. Properties, Reactions, ph, and Titration Acids and Bases Properties, Reactions, ph, and Titration C-19 2017 Properties of acids 1. Taste Sour (don t try this except with foods). 2. Are electrolytes (conduct electricity). Some are strong, some

More information

ACID-BASE TITRATION AND PH

ACID-BASE TITRATION AND PH ACID-BASE TITRATION AND PH Section 1 Aqueous Solutions and the Concept of ph Hydronium and Hydroxide Ions Acids and bases form hydroxide and hydronium ions These ions are not the only ones in an aqueous

More information

The Determination of ph of some Common Acids & Bases

The Determination of ph of some Common Acids & Bases The Determination of ph of some Common Acids & Bases Introduction: An acid is a substance that when dissolved in water produces hydrogen ions, H +. Inorganic acids do not contain carbon but organic acids

More information

Definition of Acid. HCl + H 2 O H 3 O + + Cl

Definition of Acid. HCl + H 2 O H 3 O + + Cl Acids Definition of Acid Acids are substances that contain H + ions that ionize when dissolved in water. Arrhenius acid: a compound that increases the concentration of H + ions that are present when added

More information

Chapter 10. Acids and Bases

Chapter 10. Acids and Bases Chapter 10 Acids and Bases 1 Properties of Aqueous Solutions of Acids and Bases Aqueous acidic solutions have the following properties: 1. They have a sour taste.. They change the colors of many indicators.

More information

UNIT #11: Acids and Bases ph and poh Neutralization Reactions Oxidation and Reduction

UNIT #11: Acids and Bases ph and poh Neutralization Reactions Oxidation and Reduction NAME: UNIT #11: Acids and Bases ph and poh Neutralization Reactions Oxidation and Reduction 1. SELF-IONIZATION OF WATER a) Water molecules collide, causing a very small number to ionize in a reversible

More information

Acids and Bases. A strong base is a substance that completely ionizes in aqueous solutions to give a cation and a hydroxide ion.

Acids and Bases. A strong base is a substance that completely ionizes in aqueous solutions to give a cation and a hydroxide ion. Acid-Base Theories Arrhenius Acids and Bases (1884) Acids and Bases An acid is a substance that, when dissolved in water, increases the concentration of hydrogen ions. A base is a substance that, when

More information

Duncan. UNIT 14 - Acids & Bases. COMMON ACIDS NOTES lactic acetic phosphoric NAMING ACIDS NOTES

Duncan. UNIT 14 - Acids & Bases. COMMON ACIDS NOTES lactic acetic phosphoric NAMING ACIDS NOTES COMMON ACIDS NOTES lactic acetic phosphoric citric malic PROPERTIES OF ACIDS 1. 1. PROPERTIES OF BASES 2. 2. 3. 3. 4. 4. 5. 5. NAMING ACIDS NOTES Binary acids (H + one element) 1. hydro- - HF 2. root of

More information

Bio 105 Lab 3: Chemistry: ph and solutions

Bio 105 Lab 3: Chemistry: ph and solutions 1 Bio 105 Lab 3: Chemistry: ph and solutions Part 1. Acid and Base Chemistry A. Introduction BIO 105 Summer 2013 Name One of the most important concepts in biology is acid/base chemistry. We are familiar

More information

Unit Nine Notes N C U9

Unit Nine Notes N C U9 Unit Nine Notes N C U9 I. AcidBase Theories A. Arrhenius Acids and Bases 1. Acids contain hydronium ions (H O ) commonly referred to as hydrogen ions (H ) that dissociate in water a. Different acids release

More information

CHAPTER 19. Acids, Bases, and Salts Acid Base Theories

CHAPTER 19. Acids, Bases, and Salts Acid Base Theories CHAPTER 19 Acids, Bases, and Salts 19.1 Acid Base Theories ACIDS tart or sour taste Electrolytes Strong acids are corrosive Acid Facts... indicators will change color Blue litmus paper turns pink react

More information

Lesson Five: Acids, Bases, ph, and Buffers

Lesson Five: Acids, Bases, ph, and Buffers Lesson Five: Acids, Bases, ph, and Buffers Arrhenius Acids and Bases Acids and bases can be defined a number of ways. One of the oldest and most common ways is the definition according to Arrhenius, named

More information

Definitions. Acids give off Hydrogen ions (protons) Bases give off hydroxide ions

Definitions. Acids give off Hydrogen ions (protons) Bases give off hydroxide ions Acids and Bases Arrhenius- Definitions Acids give off Hydrogen ions (protons) Bases give off hydroxide ions This definition did not include enough acids but does explain many. Brønsted-Lowry Acids are

More information

Contents and Concepts

Contents and Concepts Chapter 16 1 Learning Objectives Acid Base Concepts Arrhenius Concept of Acids and Base a. Define acid and base according to the Arrhenius concept. Brønsted Lowry Concept of Acids and Bases a. Define acid

More information

Acids and Bases. Dr. Diala Abu-Hassan, DDS, PhD Lecture 2 Nursing First Semester 014. Dr. Diala Abu-Hassan 1

Acids and Bases. Dr. Diala Abu-Hassan, DDS, PhD Lecture 2 Nursing First Semester 014. Dr. Diala Abu-Hassan 1 science.lotsoflessons.com Acids and Bases, DDS, PhD Dr.abuhassand@gmail.com Lecture 2 Nursing First Semester 014 1 Outline Definitions of acids and bases Acid and base strength The dissociation constant

More information

g. Looking at the equation, one can conclude that H 2 O has accepted a proton from HONH 3 HONH 3

g. Looking at the equation, one can conclude that H 2 O has accepted a proton from HONH 3 HONH 3 Chapter 14 Acids and Bases I. Bronsted Lowry Acids and Bases a. According to Brønsted- Lowry, an acid is a proton donor and a base is a proton acceptor. Therefore, in an acid- base reaction, a proton (H

More information

Acids, Bases and Salts. Chapters 19

Acids, Bases and Salts. Chapters 19 Acids, Bases and Salts Chapters 19 Acid - Base Theories Section 19.1 What are common examples of acids and bases? What properties do you know about acids and bases? Arrhenius acids In 1887 A swedish Chemist,

More information

Grace King High School Chemistry Test Review

Grace King High School Chemistry Test Review CHAPTER 19 Acids, Bases & Salts 1. ACIDS Grace King High School Chemistry Test Review UNITS 7 SOLUTIONS &ACIDS & BASES Arrhenius definition of Acid: Contain Hydrogen and produce Hydrogen ion (aka proton),

More information

ACIDS, BASES & SALTS DR. RUCHIKA YADU

ACIDS, BASES & SALTS DR. RUCHIKA YADU ACIDS, BASES & SALTS DR. RUCHIKA YADU Properties of Acids Acid is a compound which yields hydrogen ion (H+), when dissolved in water. Acid is sour to the taste and corrosive in nature. The ph value of

More information

CHM 130 Acid-Base Titration Molarity of Acetic Acid in Vinegar

CHM 130 Acid-Base Titration Molarity of Acetic Acid in Vinegar CHM 130 Acid-Base Titration Molarity of Acetic Acid in Vinegar INTRODUCTION One of the most important techniques for chemical analysis is titration to an equivalence point. To illustrate this procedure,

More information

Acids, Bases, & Neutralization Chapter 20 & 21 Assignment & Problem Set

Acids, Bases, & Neutralization Chapter 20 & 21 Assignment & Problem Set Acids, Bases, & Neutralization Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Acids, Bases, & Neutralization 2 Study Guide: Things You Must Know

More information

Acids and Bases. Feb 28 4:40 PM

Acids and Bases. Feb 28 4:40 PM Acids and Bases H O s O Cl H O O H H N H Na O H H Feb 28 4:40 PM Properties of Acids 1. Taste sour 2. Conduct electrical current 3. Liberate H 2 gas when reacted with a metal. 4. Cause certain dyes to

More information

Chapter 14 Acids and Bases

Chapter 14 Acids and Bases Chapter 14 Acids and Bases General Properties of Acids 1. An acid tastes sour - acidus = Latin, sour; acetum= Latin, vinegar 2. An acid turns indicator dye litmus from blue to red. 3. An acid reacts with

More information

Chapter 14: Acids and Bases

Chapter 14: Acids and Bases Chapter 14: Acids and Bases Properties of Acids and Bases What is an acid? Some examples of common items containing acids: Vinegar contains acetic acid; lemons and citrus fruits contain citric acid; many

More information

Acids and Bases. Bases react with acids to form water and a salt. Bases do not commonly with metals.

Acids and Bases. Bases react with acids to form water and a salt. Bases do not commonly with metals. Acids and Bases Properties of Acids and Bases Acids taste. Lemon juice and, for example, are both aqueous solutions of acids. Acids conduct electricity; they are. Some are strong electrolytes, while others

More information

Chapters 15 & 16 ACIDS & BASES ph & Titrations

Chapters 15 & 16 ACIDS & BASES ph & Titrations PROPERTIES OF ACIDS Chapters 15 & 16 ACIDS & BASES ph & Titrations There are 5 main properties of acids: 1. sour taste 2. change the color of acidbase indicators 3. react with metals to produce H2 gas

More information

ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA

ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA Acids- taste sour Bases(alkali)- taste bitter and feel slippery Arrhenius concept- acids produce hydrogen ions in aqueous solution while

More information

Acids and Bases. How does ph affect biological solutions? Introduction. Prelab Preparation Review Section 2.3 on acids and bases in your textbook.

Acids and Bases. How does ph affect biological solutions? Introduction. Prelab Preparation Review Section 2.3 on acids and bases in your textbook. Acids and Bases How does ph affect biological solutions? Learning Objectives To relate the ph scale to how acidic or basic a solution is. To explain how a buffer affects the ph of a solution. Process Objectives

More information

Definition of Acid. HCl + H 2 O H 3 O + + Cl

Definition of Acid. HCl + H 2 O H 3 O + + Cl Acids Definition of Acid Acids are substances that contain H + ions that ionize when dissolved in water. Arrhenius acid: a compound that increases the concentration of H + ions that are present when added

More information

Acid and Bases. Physical Properties. Chemical Properties. Indicators. Corrosive when concentrated. Corrosive when concentrated.

Acid and Bases. Physical Properties. Chemical Properties. Indicators. Corrosive when concentrated. Corrosive when concentrated. Physical Properties Acid and Bases Chemistry 30 Acids Corrosive when concentrated Have a sour taste Bases Corrosive when concentrated Have a bitter taste Often have a sharp odour Chemical Properties Indicators

More information

Acids Bases and Salts Acid

Acids Bases and Salts Acid Acids Bases and Salts Acid ph less than 7.0 Sour taste Electrolyte Names of Acids Binary acids Contain only 2 elements Begin with hydro; end with ic Ternary acids Ex: H 2 S = hydrosulfuric Contain a polyatomic

More information

ACIDS & BASES PROPERTIES OF ACIDS ACIDS PROPERTIES OF ACIDS PROPERTIES OF ACIDS 11/1/2016

ACIDS & BASES PROPERTIES OF ACIDS ACIDS PROPERTIES OF ACIDS PROPERTIES OF ACIDS 11/1/2016 SC STANDARD COVERED ACIDS & BASES Standard PS-3.7 Classify various solutions as acids or bases according to their physical properties, chemical properties (including neutralization and reaction with metals),

More information

The Acidic Environment

The Acidic Environment The Acidic Environment HSC ENRICHMENT DAY Artchaki Chandrasegar & Alexander Comerford Key points of the acidic environment TODAY, WE WILL FOCUS ON: 1. Definitions: Lavoisier / Davy; Arrhenius; Brønsted-Lowry;

More information

UNIT 14 - Acids & Bases

UNIT 14 - Acids & Bases COMMON ACIDS NOTES lactic acetic phosphoric citric malic PROPERTIES OF ACIDS 1. 1. PROPERTIES OF BASES 2. 2. 3. 3. 4. 4. 5. 5. NAMING ACIDS NOTES Binary acids (H + one element) Practice: 1. hydro- - HF

More information

4.5: Acids and Bases. SCH3U: Solutions and Solubility. Properties of Pure and Aqueous Substances. Arrhenius Theory. Acid:

4.5: Acids and Bases. SCH3U: Solutions and Solubility. Properties of Pure and Aqueous Substances. Arrhenius Theory. Acid: 4.5: Acids and Bases Properties of Pure and Aqueous Substances Arrhenius Theory Acid: Acids are sour tasting and corrosive. They react readily with active metals such as Zn, Ca, Mg and carbonate-based

More information

Experiment 5E BOTTLES WITHOUT LABELS: STUDIES OF CHEMICAL REACTIONS

Experiment 5E BOTTLES WITHOUT LABELS: STUDIES OF CHEMICAL REACTIONS Experiment 5E BOTTLES WITHOUT LABELS: STUDIES OF CHEMICAL REACTIONS FV 1-21-16 MATERIALS: Eight 50 ml beakers, distilled water bottle, two 250 ml beakers, conductivity meter, ph paper (A/B/N), stirring

More information

Acid-Base Titration Acetic Acid Content of Vinegar

Acid-Base Titration Acetic Acid Content of Vinegar Acid-Base Titration Acetic Acid Content of Vinegar Prelab Assignment Read the entire lab. Write an objective and any hazards associated with this lab in your laboratory notebook. On a separate sheet of

More information

Acids and Bases. Two important classification of compounds - Acids and Bases. Properties of BASES

Acids and Bases. Two important classification of compounds - Acids and Bases. Properties of BASES ACIDS AND BASES Acids and Bases Two important classification of compounds - Acids and Bases Properties of ACIDS Taste Sour/Tart Stings and burns the skin Reacts with bases Turns blue litmus paper red Reacts

More information

Introduction to Acids & Bases II. Packet #26

Introduction to Acids & Bases II. Packet #26 Introduction to Acids & Bases II Packet #26 1 Review I Svante Arrhenius was the first person to recognize the essential nature of acids and bases. 2 Review II Arrhenius postulated that: Acids produce hydrogen

More information

Properties of Acids and Bases

Properties of Acids and Bases Chapter 15 Aqueous Equilibria: Acids and Bases Properties of Acids and Bases Generally, an acid is a compound that releases hydrogen ions, H +, into water. Blue litmus is used to test for acids. Blue litmus

More information

CH19 Bronsted-Lowry Definitions

CH19 Bronsted-Lowry Definitions CH19 Bronsted-Lowry Definitions 1 BRONSTED-LOWRY DEFINITIONS [Acids] An acid is a substance that can donate H + ions HCl hydrochloric acid HNO 3 nitric acid HOAc acetic acid H 3 0 + hydronium ion NH +

More information

CHEMISTRY. Chapter 16 Acid-Base Equilibria

CHEMISTRY. Chapter 16 Acid-Base Equilibria CHEMISTRY The Central Science 8 th Edition Chapter 16 Acid-Base Equilibria Kozet YAPSAKLI Why study acids bases? bases are common in the everyday world as well as in the lab. Some common acidic products

More information

Aims to increases students understanding of: History, nature and practice of chemistry. Applications and uses of chemistry

Aims to increases students understanding of: History, nature and practice of chemistry. Applications and uses of chemistry Aims to increases students understanding of: History, nature and practice of chemistry Applications and uses of chemistry Implications of chemistry for society and the environment 1. Definitions: Lavoisier

More information

Acids & Bases. Chapter 17

Acids & Bases. Chapter 17 Acids & Bases Chapter 17 Arrhenius Definition: Classic Definition of Acids and Bases Acid: A substance that increases the hydrogen ion concetration, [H + ], (also thought of as hydronium ion, H 3 O + )

More information

Acids, Bases, Salts, and Buffers

Acids, Bases, Salts, and Buffers Acids, Bases, Salts, and Buffers Investigation questions Parts 1 and 2 What is ph and how is it related to the identity and concentration of the substance in a solution? What is a salt? Introduction I.

More information

CHAPTER Acid & Base

CHAPTER Acid & Base CHAPTER 19 19.1 Acid & Base Common Reactions with Acids Dilute: small amount of solute 1-M Concentrated: large amount of solute Indicator: changes color to show the presence of acids or bases : eat or

More information

Aqueous Reactions and Solution Stoichiometry (continuation)

Aqueous Reactions and Solution Stoichiometry (continuation) Aqueous Reactions and Solution Stoichiometry (continuation) 1. Electrolytes and non-electrolytes 2. Determining Moles of Ions in Aqueous Solutions of Ionic Compounds 3. Acids and Bases 4. Acid Strength

More information

Chem 1046 Lecture Notes Chapter 17

Chem 1046 Lecture Notes Chapter 17 Chem 1046 Lecture Notes Chapter 17 Updated 01-Oct-2012 The Chemistry of Acids and Bases These Notes are to SUPPLIMENT the Text, They do NOT Replace reading the Text Book Material. Additional material that

More information

Name: Date: Number: Acids

Name: Date: Number: Acids Acids The sour taste of the lemon juice tells us that it is an acid. Acids are special kinds of chemicals. They are common in everyday life. Some are helpful, others are harmful. There are some that are

More information

Acids and Bases Unit 13

Acids and Bases Unit 13 Acids and Bases Unit 13 Chemistry of Acids and Bases 1. Watch video and complete worksheet Standard Deviants Teaching Systems: Chemistry: Module 05: Acids and Bases http://app.discoveryeducation.com/player/view/asset

More information

1. Know and be capable of applying the Bronsted-Lowery model of acids and bases (inculdig the concepts related to conjugate acid-base pairs.

1. Know and be capable of applying the Bronsted-Lowery model of acids and bases (inculdig the concepts related to conjugate acid-base pairs. Acid-Base Equilibria You have just completed a chapter on equilibrium. That chapter focused primarily on gas phase reactions (with a few exceptions). This section on Acid-Base equilibria (along with the

More information

Experiment 7 Buffer Capacity & Buffer Preparation

Experiment 7 Buffer Capacity & Buffer Preparation Chem 1B Dr. White 57 Experiment 7 Buffer Capacity & Buffer Preparation Objectives To learn how to choose a suitable conjugate acid- base pair for making a buffer of a given ph To gain experience in using

More information

Acids, Bases, and Buffers

Acids, Bases, and Buffers Print Presentation Acids, Bases, and Buffers OVERVIEW You're probably familiar with acids and bases in the products you use at home. Rust removers often contain phosphoric acid. Muriatic acid (a common

More information

INTRODUCTION TO ACIDS AND BASES

INTRODUCTION TO ACIDS AND BASES INTRODUCTION TO ACIDS AND BASES ALIGNED STANDARDS S.C. 912.P.8.11 Relate acidity and basicity to hydronium and hydroxide concentration and ph. S.C.912.N.1.2 Describe and explain what characterizes science

More information

Water, the SPECIAL Equilibrium

Water, the SPECIAL Equilibrium THE ACID TEST Water, the SPECIAL Equilibrium I. Characteristics of Water A. Water are highly. B. They are in continuous. C. Always. D. Water is dense in the solid phase than in the phase. i.e. ice floats

More information

The ph of aqueous salt solutions

The ph of aqueous salt solutions The ph of aqueous salt solutions Sometimes (most times), the salt of an acid-base neutralization reaction can influence the acid/base properties of water. NaCl dissolved in water: ph = 7 NaC 2 H 3 O 2

More information

H = Hydrogen atoms O = Oxygen atoms

H = Hydrogen atoms O = Oxygen atoms CHEMISTRY CP Name: KEY Period: TEST DATE: Unit 8 Review Sheet KEY: Properties of Water, Solutions, Concentration, Acids and Bases PROPERTIES OF WATER 1. Define the following terms: polarity, surface tension,

More information

Acids and Bases. How do acids and bases behave in water? Acid or Base Acetic acid HC 2. (aq) Vinegar Sour Red Yes Acid Benzoic acid HC 7

Acids and Bases. How do acids and bases behave in water? Acid or Base Acetic acid HC 2. (aq) Vinegar Sour Red Yes Acid Benzoic acid HC 7 Why? Acids and Bases How do acids and bases behave in water? Acids and bases play an important role in our lives. Numerous biological processes, industrial applications, and even environmental problems

More information

Chapter 3: Solution Chemistry (For best results when printing these notes, use the pdf version of this file)

Chapter 3: Solution Chemistry (For best results when printing these notes, use the pdf version of this file) Chapter 3: Solution Chemistry (For best results when printing these notes, use the pdf version of this file) Section 3.1: Solubility Rules (For Ionic Compounds in Water) Section 3.1.1: Introduction Solubility

More information

ACIDS AND BASES 4/19/15. 1) Given the reactions:

ACIDS AND BASES 4/19/15. 1) Given the reactions: NAME: ACIDS AND BASES 4/19/15 ROW PD 1) Given the reactions: (A) NH3(g) + H2O(l) NH4 + + OH (B) HCl + H2O (l) H3O + + Cl As shown in equations (A) and (B) and based on the Bronsted theory, water is an

More information

Objectives To prepare a dilute solution of a weak acid. To prepare a buffer of a specific ph value.

Objectives To prepare a dilute solution of a weak acid. To prepare a buffer of a specific ph value. E x p e r i m e n t Chemistry Is phun! Objectives To prepare a dilute solution of a weak acid. To prepare a buffer of a specific ph value. To observe the effects of adding acid and base to a buffer solution.

More information

19.3 Strengths of Acids and Bases > Chapter 19 Acids, Bases, and Salts Strengths of Acids and Bases

19.3 Strengths of Acids and Bases > Chapter 19 Acids, Bases, and Salts Strengths of Acids and Bases Chapter 19 Acids, Bases, and Salts 19.1 Acid-Base Theories 19.2 Hydrogen Ions and Acidity 19.3 Strengths of Acids and Bases 19.4 Neutralization Reactions 19.5 Salts in Solution 1 Copyright Pearson Education,

More information

Obj: Observe and describe neutralization reactions. Copy: Write the balanced chemical equation for the neutralization of HCl with KOH.

Obj: Observe and describe neutralization reactions. Copy: Write the balanced chemical equation for the neutralization of HCl with KOH. Do Now Date: April 13, 2015 Obj: Observe and describe neutralization reactions. Copy: Write the balanced chemical equation for the neutralization of HCl with KOH. HCl + KOH KCl(aq) + H 2 O(l) Practice

More information

Acid Base Equilibria

Acid Base Equilibria Acid Base Equilibria Acid Ionization, also known as acid dissociation, is the process in where an acid reacts with water to produce a hydrogen ion and the conjugate base ion. HC 2 H 3 O 2(aq) H + (aq)

More information

CALCULATIONS INVOLVING STRONG ACIDS & BASES. Write the ionization equation (strong acid) or dissociation equation (strong base)

CALCULATIONS INVOLVING STRONG ACIDS & BASES. Write the ionization equation (strong acid) or dissociation equation (strong base) 1 CALCULATIONS INVOLVING STRONG ACIDS & BASES 1. Finding H 3 O + (aq) ) from strong acid concentrations and OH - (aq) from strong base concentrations 2. Finding H 3 O + (aq) and OH - (aq) using K w. 3.

More information