HCl and HNO 3 are monoprotic meaning Sulfuric acid is, 2 Protons (also called polyprotic) Phosphoric acid is, 3 protons. (also called polyprotic)

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1 Acid and Base packet Page 1 of 13 Honors Chemistry Acids and Bases Quiz: Test: Project: Vocabulary: 1Alkaline 6 diprotic acid 11 neutralization 16 salt 21 triprotic acid 2 amphoteric 7 end point 12 oxyacid 17 standard solution 3 (Arrhenius) acid 8 Hydronium 13 ph 18 Strong acid 22Weak acid 4 (Arrhenius) base 9 Hydroxide 14 Poh 19 strong base 5 Binary acid 10 monoprotic acid 15 polyprotic acid 20 Titration 23 weak base COMMON ACIDS Memorize Hydrochloric Acid HCl Nitric Acid HNO3 Acetic Acid HC2H3O2 Sulfuric Acid H2SO4 ACIDS, BASES & SALTS NAMING ACIDS Binary vs oxyacids COMMON STRONG ACIDS (MEMORIZE): HCl HNO3 HClO4 sulfuric acid COMMON WEAK ACIDS (MEMORIZE) Hydrofluoric acetic acid H2CO3 H3PO4 HCl and HNO 3 are monoprotic meaning Sulfuric acid is, 2 Protons (also called polyprotic) Phosphoric acid is, 3 protons. (also called polyprotic) A binary acid contains only 2 elements (H + other). Examples: They are named using the prefix hydro- the root of the element and ic. Name: HF, HCl, HBr and HI Oxyacids are composed of H, O and a 3 rd element an example is Common acids: Sulfuric: # 1 industrial chemical, used in making Effective dehydrator and is found in acid rain and automobile batteries Phosphoric also in Nitric used to make Hydrochloric: common lab acid, found in your Acetic: found in

2 Acid and Base packet Page 2 of 13 PROPERTIES OF ACIDS: 1. Sour taste ex s: citric acid in lemons, oranges and grapefruit, maleic acid in apples, acetic acid in vinegar and lactic acid in sour milk. 2. Contain hydrogen, some react with metals to release HYDROGEN gas. Write the balanced equation with state symbols for the reaction of zinc metal with hydrochloric acid (HCl): 3. Acids change the color of dyes know as indicators. Example of an indicator: pool ph test strips * litmus= turns pink for acid, blue for base *phenolphthalein= turns pink with bases 4. Acids react with bases to produce : a salt and water = NEUTRALIZATION reaction 5. Acids are electrolytes, - they will conduct electricity as a solution. Definitions for acid: Arrhenius (traditional definition): cmpd containing hydrogens and ionizes in aqueous soln to form hydronium ions: Example: nitric acid HNO3 + H2O H3O + + NO3 - hydronium ion (H + or H3O + ) Strong acids are strong electrolytes they ionize completely in aqueous soln (completely breakdown). Remember electrolytes conduct a current in solution. Weak acids are weak electrolytes they ionize partially in aqueous soln (in equilibrium partially break down). Remember electrolytes conduct a current in solution. We can write a Ka for their dissociation PROPERTIES OF BASES: 1. Have a bitter taste, ex: soap 2. Feel slippery 3. Change color of indicators 4. React with acids to make salts and water 5. Are electrolytes, conduct a current as a solution Traditional definition (Arrhenius def) of a base: Contains hydroxide: In a neutralization reaction an acid and a base react to form a salt and water. Neutralization reactions are often double displacement reactions. Practice neutralization reactions: name the acid and circle the salt in the final answer! 1. HCl + NaOH + acid name: 2. H2SO4 + KOH + acid name: 3. HBr + Mg(OH)2 + acid name: 4. HC2H3O2 + NaOH + acid name: 5. Ca(OH)2 and H3PO4 + acid name:

3 Acid and Base packet Page 3 of 13 Types of bases: Strong: hydroxides of metals in I and II Ex:, and. Strong electrolytes Weak: hydroxides of many transition metals ex Fe(OH)3 and organic compounds containing nitrogen Example: ammonia= NH3. A solution that contains OH- from a soluble base is referred to as: anhydrous means without water, so anhydrides are acids or bases that have had water removed. Metallic oxides generally form bases and nonmetallic oxides generally form acids. See ref packet pg 6 Water is amphoteric it can act as an acid or a base Buffer: solution that can resist changes in ph, usually made up of a weak acid or base and a salt of the weak acid or base. Examples: blood, sea water The ph Scale The ph scale ranges from 0 to 14. It measures the acidity or basicity of a solution. A ph of 7 means it is a neutral solution. Pure water has a ph of 7. A ph of less than 7 means the solution is acidic. A ph of more than 7 means the solution is basic. The less ph, the more acidic the solution is. The more ph, the more basic the solution is. ph stands for the power of H, or the amount of H + ions acids or bases take or contribute in solution. ph equals the negative log of the concentration of H +. ph = -log[h + ]

4 Acid and Base packet Page 4 of 13 WHAT REALLY HAPPENS Acids are compounds that break into hydrogen (H+) ions and another compound when placed in an aqueous solution. Bases are compounds that break up into hydroxide (OH-) ions and another compound when placed in an aqueous solution. Let's change the wording a bit. If you have an ionic compound and you put it in water, it will break apart into two ions. If one of those ions is H+, the solution is acidic. If one of the ions is OH-, the solution is basic. There are other ions that make acidic and basic solutions, but we won't be talking about them here. That ph scale we talked about is actually a measure of the number of H+ ions in a solution. If there are a lot of H+ ions, the ph is very low. If there are a lot of OH- ions, that means the number of H+ ions is very low, so the ph is high. Notes on ph Aqueous solution: Water is self-ionized (slightly) breaks down partially on its own. Example: 2 H2O H3O + + OH - Reversible reaction reaches equilibrium some of the water breaks down into hydronium H3O + (or H + ) and hydroxide OH NOTE: Hydronium can be written as either H3O + or its abbreviated form H + Pure water has: 1 x 10-7 M H + and 1 x 10-7 M OH - Because [H + ] = [OH-] in pure water it is neutral if [H + ] > [OH-] = acidic if [OH-] > [H + ] = basic (remember [ ] indicates molar concentration) In all aqueous solutions: [H + ] [OH-] = 1 x (at 25 0 C) Example: Calculate [H3O + ] and [OH-] for 1 x10-4 M nitric acid. Example 2: Calculate [H3O + ] and [OH-] for 0.02 M Ba(OH)2 You try: Calculate [H + ] and [OH-] for 1 x 10-3 M H2SO4

5 Acid and Base packet Page 5 of 13 Mathematically, it is possible to have a ph below 0 or above 14. We will not go outside of that range All six equations: in reference packet! ph = -log [H + ] poh = -log [OH-] [H + ] = 10 ph [OH-] = 10 poh [H + ] [OH-] = 1 x10-14 ph + poh = 14 logarithm = the power to which 10 must be raised to get that number. Example: log 10 7 = 7 log 10-3 = -3 etc. You can calculate the log by inspection only when you have a perfect base 10 otherwise use the log button on your calculator Example: What is the ph of M NaOH? Copy work Example 2: what is the ph of 3.4 x 10-3 M H2SO4? You try: What is the ph of 1.2 x 10-3 M Mg(OH)2? To find concentration from ph use [H + ] = 10 ph (in packet) Use the 10 x key second function above the log button DO NOT use the exp key!!! Example: what is the [H + ] of a solution with a ph of 7.52? You try : what is the hydroxide concentration of a solution with a ph of 3.2? poh scale opposite of the ph scale on the poh scale bases have low numbers and acids have high numbers! Example: What is the [H+] of a solution with a poh of 8.2? You try: What is the poh of a solution with an [H+] =6.5 x 10-5?

6 Acid and Base packet Page 6 of 13 Acid Rain Reading Questions 1. At what ph does acidic rainfall become a concern? 2. How are plants harmed by acid rain (according to the author)? 3. Why would non-polluted rural areas be concerned about acid rain? 4. What acid anhydride normally exists in non-polluted air making rain acidic? NAMES TO KNOW Here are a couple of definitions you should know: Acid: A solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp". Base: A solution that has an excess of OH- ions. Another word for base is alkali. Aqueous: A solution that is mainly water. Think about the word aquarium. AQUA means water. Strong Acid: An acid that has a very low ph (0-4). Strong Base: A base that has a very high ph (10-14). Weak Acid: An acid that only partially ionizes in an aqueous solution. That means not every molecule breaks apart. They usually have a ph close to 7 (3-6). Weak Base: A base that only partially ionizes in an aqueous solution. That means not every molecule breaks apart. They usually have a ph close to 7 (8-10). Neutral: A solution that has a ph of 7. It is neither acidic nor basic.

7 Acid and Base packet Page 7 of 13 Titration notes In a titration you have two solutions (typically one is an acid and one is a base). You know the concentration of one solution (the standard) and you are trying to calculate the concentration of the unknown. This is done by using an indicator and slowly mixing the two solutions together until you get a color change (which indicates the end point!). When the color changes you use your two volumes (the volume of the standard and the volume of the unknown) along with the concentration of the known to calculate the unknown s concentration. We will do math calculations in class and then in our formal lab we will complete an actual titration. End point (equivalence point): Rapid change in ph, there are equivalent amounts of H + and OH, the equivalence point does not always occur at a ph of 7 see graphs below. (depends on whether you have a strong or weak acid/base)/ Indicators & the ph scale: the best indicator in a titration is based on the ph at the equivalence pt: Examples of titration curves! Graphs of data from titration experiments. Which indicator should we use for curve A curve B? Which indicator would be pink when the [H+] = 1 x 10-4? You try which indicator would be blue when [H+] = 3.2 x10-12? We will use a buret in our titrations they measure the volume released from the buret they are read from the top down (zero is at the top and ml is at the bottom): Ex: you try:

8 Acid and Base packet Page 8 of 13 Working titration problems you can use the formula: MaVa na = MbVb nb M = molarity (of acid or base) V = volume of acid or base and na = moles of H+ in the acid and nb = moles of OH- in the base. Example: In a titration, 27.4 ml of a standard solution of Ba(OH)2 is added to 20.0 ml of HCl. The concentration of the Ba(OH)2 is M. What is the Molarity of HCl? You try: it takes 25 ml of 0.20 M H2SO4 to neutralize 37 ml of NaOH what is the molarity of the NaOH? EXTRA PRACTICE: Calculate the ph of the solutions below M HCl M H2SO M NaOH M Ca(OH) M KOH 6. What is the [H3O + ] of a solution with a ph of 6.7? (remember [H3O + ] = [H+]) 7. What is the [OH-] of a solution with a ph of 9.5? 8. What is the ph of a solution with a poh of 12.5? 9. What is the [H+] of a solution with a poh of 3.5? 10. What is the ph of a solution with a [OH-] of 2.3 x 10-6? Is this an acid or a base? 11. What is the poh of a solution with a [H+] of 1.7 x 10-6? 12. What is the [OH-] of a solution with a ph of 6.3? 13. What is the ph of a M solution of Be(OH)2? 14. What is the [H+], [OH-], ph and poh of 0.22 M H2SO4?

9 Acid and Base packet Page 9 of 13 Titration practice sheet To determine the concentration of an acid (or base), we can react it with a base (or acid of known concentration until it is completely neutralized. The point of complete neutralization is the endpoint noted by the color change of the indicator. 1. Why do you need to use an indicator when titrating a solution? 2. If 20.0 ml of M HCl is required to neutralize 30.0 ml of NaOH determine the molarity of the NaOH solution. 3. Suppose that 20.0 ml of 0.10 M Ca(OH)2 is required to neutralize 12.0 ml of HCl what is the molarity of the acid? 4. How much 2.2 M Ba(OH)2 is required to neutralized 15.0 ml of 1.75 M H2SO4? 5. What is the concentration of 50 ml of sulfuric acid that requires 25 ml of 2.0 M potassium hydroxide to be completely neutralized? 6. What volume of 1.25 M Ca(OH)2 is required to titrate 36 ml of 1.77 M HCl? 7. Given the reaction: Ba(OH)2 + 2HClO4 Ba(ClO4) 2 + 2HOH 95.5 ml sample of Ba(OH)2 is neutralized to completion with 75.0 ml of 0.8 M HClO4. Determine the concentration of Ba(OH)2. 8. A 10.0 ml sample of H2SO4 was exactly neutralized by 13.5 ml of 1.0 M KOH what is the molartiy of the sulfuric acid?

10 Review on Acids, Bases, ph, and Titrations Find the ph of the following solutions. 1. a 0.08 M HCl solution Acid and Base packet Page 10 of a 0.11 M Mg(OH)2 3. a solution with a poh of a solution with [H3O+] = 5.6 x What is the poh of a solution with a [H+] = 2.3 x 10-8? 6.What is the OH- concentration of a solution with a ph = 3.66? 7.What is the H+ concentration of a solution with a hydroxide ion concentration of 4.7 x 10-3 M? 8. What is the [OH-], [H3O+], ph and poh of a M H2SO4? 9.What is the molarity of 1.5L of a hydrochloric acid solution that requires 790 ml of 2.8 M sodium hydroxide to be titrated? 10. If it requires 90 ml of 1.0 M sulfuric acid to titrate 150 ml of potassium hydroxide, what is the concentration of the KOH? 11. What is the molarity of 1.75 L of HNO3 titrated with 560 ml of 1.28 M LiOH? 12. How many liters of 0.5 M RbOH are required to completely titrate 750 ml of 0.1 M HCl? 13. List the 5 properties of acids 14. List the 5 properties of bases 15. Write the formula or name for A. HCl, B. H2SO4, C. HNO3, D. HC2H3O2, E. phosphoric acid, F. perchloric acid, G. Hydrofluoric acid and H. carbonic acid 16. Which of the above are diprotic acids? 17. Which of the above are oxyacids? 18. Which of the above are binary acids? 19. Which of the above is found in your stomach? 20. Which of the above is used to make explosives? 21. Which of the above is found in vinegar? 22. Which of the following is a salt: A. KOH B. KCL C. HOH D. HCL? Answers 1) 1.1 2) ) 5.7 4) ) ) 4.6 x ) 2.13 x ) 1 x 10-13, 0.1, 1, 13 9) 1.5 M HCl 10) 1.2 M KOH 11).41 M HNO3 12).15L RbOH 13. Sour taste, react with metals to produce hydrogen gas, changes the colors of indicators, reacts with bases to form salts and water (neutralization), are electrolytes. 14.Bitter taste, feel slippery, changes the colors of indicators, reacts with acids to form salts and water (neutralization), are electrolytes. 15 A. Hydrochloric B. Sulfuric C nitric D acetic E. H3PO4 F. HClO4 G. HF H H2CO3 16 B and H 17. B, C, D, E, F, H 18 A and G 19 A 20. C 21. D 22 B ionic copmpound

11 Acid and Base packet Page 11 of 13 Acid-Base Titration Lab Pre-lab Questions- Use notes on pg 7 to answer 1. What is a titration? Name: pd: 2.What is an equivalence point? 3.Why are titrations done? Objectives: To complete an acid- base titration To practice using a buret To use lab data to calculate the concentration of an unknown solution. Safety: Full MSDS sheets are in the MSDS folder in the lab room. MSDS health information: HC2H3O2, NaOH and phenolphthalein Health Effects: may cause skin irritation, eye irritation, gastrointestinal irritation First Aid: eyes: flush with water for 15 minutes. Skin flush with soap and water for 15 minutes Ingestion: give 2-4 cups of milk or water get medical attention Equipment: Beakers, Flask, pipet, buret, buret clamp, ring stand, phenopthalein, M NaOH,? M HC2H3O2 Procedure: 1. Use small graduated cylinder & place 10.0 ml of the acid - HC2H3O2 into a clean Erlenmeyer flask. 2. Add 2-3 drops of phenolphthaleinindicator to the acid solution. Set to the side. 3. Record the initial buret reading. 4. Place the flask under the buret (place a piece of clean white paper under the flask to make it easier to observe). 5. Begin titrating by adding small amounts of base to the flask (slightly turn the stopcock to allow small amounts of base out be sure to add the base slowly!) Horizontal = CLOSED Vertical = FULLY OPEN 6. Gently swirl the solution after each addition. 7. When localized pink spots appear and then disappear, reduce the size of additions to dropwise. Ms. Clark will show you how to add a half drop. 8. When one drop of base produces a faint pink color that persists with swirling the endpoint has been reached. Record the final buret reading. 9. Repeat the titration with a second sample of acid redo steps 3-5; your buret does not need to be refilled. Just record the initial buret reading before starting the second titration process. 10. Clean up excess acid and base may go down the drain with plenty of water. If you are not the last class leave the burets set up for the next class! th pd drain burets = Ms.Clark come around with vinegar water to rinse burets out. NOTE: You do NOT want your sample to look HOT pink. You want a pale pink color to remain. You get two shots to get it right!

12 Acid and Base packet Page 12 of 13 Data Table: include units and use correct significant digits Trial One Trial Two Trial three 1. M of NaOH (Mb) M M M 2. Volume of HC2H3O2 (Va) 10.0 ml 10.0 ml 10.0 ml 3 Intial buret reading of NaOH 4. final buret reading fill in this part of the data table after the lab! Show work below in question section! 5. volume of NaOH used in titration (subtract #4 - # 3) (Vb) 6. Calculated M of HC2H3O2 (Ma) 7. Average Ma of HC2H3O2 (avg of three answers in #6) Calculations: Show all work credit will not be given without supporting work. Include units! 8. Calculate the volume of base used in each trial. (Show how you calculated answer for #5) 9. Write a balanced equation for the reaction between the acid and base. (water IS NOT a reactant use the state symbol aq to indicate water has been added) Use state symbols! 10. Calculate the M of HC2H3O2 for each trial (when using your na, use na = 1 because HC2H3O2 only loses the first H in a titration.) (Show how you calculated answer for #6) 11. Calculate the average M of HC2H3O2 (Show how you calculated answer for #7) 12. What is the concentration of 75.0 ml of NaOH titrated by 100 ml of 1.2 M hydrochloric acid? 13. How much 0.68 M carbonic acid would be required to titrate 250 ml of 0.2 M lithium hydroxide?

13 Acid and Base packet Page 13 of 13 Questions: 14. Why did Ms. Clark rinse the buret out with a 5 ml portion of the base before beginning the titration. 15. Why would your sample turn bright pink if you added too much base? 16. What would happen if you forgot to add the phenopthalein to your sample? Conclusion: 17. In a titration you have two solutions (typically one is an acid and one is a base). You know the concentration of one solution called the and you are trying to calculate the concentration of the unknown. This is done by using an indicator and slowly mixing the two solutions together until you get a color change (which indicates the end point!). My favorite part of this lab was.