Acids and Bases OTHS Academic Chemistry

Transcription

1 Name Objectives: Acids and Bases OTHS Academic Chemistry Period Define acids and bases and distinguish between Arrhenius and Bronsted-Lowry definitions Distinguish between degrees of dissociation for strong and weak acids and bases Understand, differentiate, and predict products among acid-base reactions, Define ph and use the hydrogen or hydroxide ion concentrations to calculate the ph of a solution Vocabulary: acid, base, alkaline, ph scale, bitter, sour, conjugate acid, conjugate base, neutralization, dissociation, complete ionization, soluble, Molarity, electrolyte, logarithm, titration, indicator, buret, equivalence point, end point, and coefficient Memorize: Acid/Base Nomenclature Provided: ph + poh= 14 [H + ] x [OH - ]= 1.0 x ph= -log [H + ] poh= -log [OH - ] [H + ]= 10^-pH [OH -]=10^-pOH ph poh Solution type = 7 = 7 Neutral < 7 > 7 Acidic > 7 < 7 Basic nb Ma Va = na Mb Vb CHECKLIST: How to be successful in OTHS Academic Chemistry Pay attention and take notes in class Ask questions in class on material that is not clear Work every page in the practice packet for the unit Check answers to the practice packet online at Come to tutorials with any chemistry teacher Do the online homework and check solutions once they become available Always do the practice test for every test & ask good questions on review day Keep up with the calendar for the class/be aware of approaching quizzes, tests, & other deadlines Use videos posted on website as a quick and convenient tutorial Read chapter in the book pg1 pg2 pg3 pg4 pg5 pg6 pg7 pg8

2 Name Per. Note that H 3 O + ions are hydrated hydrogen ions. H + and H 3 O + are interchangeable. H + + H 2 O = H 3 O + 1

3 Name: Period: Properties and Identification of ACIDS, BASES AND SALTS SECTION 1: IDENTIFICATION - Identify the following examples as: A = acid B = base S = salt Remember from the previous units, a salt is any ionic compound, excluding what we classify as a base. 1. AgOH 2. MgSO 4 3. ZnCO 3 4. H 2 SO 4 5. NaOH 6. HClO 7. Mg(OH) 2 8. HNO 3 9. Pb(ClO) (NH 4 ) 2 CO HC 2 H 3 O HBr SECTION 2: PROPERTIES Determine if each of the following is an acid (A) or a base (B) using the descriptions listed. 13. A cleaning solution turns litmus paper blue. 14. Your breakfast juice tasted sour. 15. The substance you are analyzing in lab has a greater concentration of H + than OH The face wash you used this morning felt slippery. 17. The battery in your remote control was alkaline. 18. The bumper on your car started to corrode because the rain water had a ph of Your mom washed your mouth out with soap (you probably deserved it) and it tasted bitter. 20. Drinking too much Coke is bad for my teeth and it will turn litmus paper red. 21. The bleach I spilled on my favorite shirt had a ph of The Drano that I used to unclog the drain has more OH - ions than H + ions. SECTION 3: ELECTROLYTES Using your notes, determine if each of the following is an electrolyte (E) or nonelectrolyte (N). Remember, soluble salts make ions in solution, so they are also electrolytes. If a compound is not a strong acid, strong base or soluble salt, it is a nonelectrolyte and does not produce ions in solution. 23. HCl 24. CO NaOH 26. HClO NaNO KOH 29. HNO C 6 H 12 O LiOH 32. H 2 SO HI 34. Na 2 SO 3 2

4 Name Per. Practice Worksheet: Acid/Base Nomenclature Decide whether each is an acid or base, and then write formulas: 1. sulfuric acid 2. chloric acid 3. magnesium hydroxide 4. nitric acid 5. hydrofluoric acid 6. sodium hydroxide 7. phosphorous acid 8. ammonia 9. calcium hydroxide 10. hydrobromic acid Decide whether each is an acid or base, and then write names: 11. H 2 CO Al(OH) H 3 PO HClO KOH 16. HCl 17. HNO Ba(OH) H 2 SO HCN 3

5 Name: Part I: Discovering the math behind ph phooey! Period: Instructions: The following data table contains some data collected in a lab by students just like you. I have added some additional information to help you understand and make connections between the values for ph and the math used to determine these values from concentration. Complete this table by adding in the missing values: Substance Acidic or Basic? ph [H + ] (in decimal) [H + ] (in scientific notation) Stomach acid (0.1 M HCl) Acidic 0.1 M 1.0 x 10-1 M Clear Soda M Rain Water Acidic 1.0 x 10-6 M Distilled Water M Alcohol Neutral Salt Water M Washing soda Basic x 10-8 M Ammonia M 1.0 x M Drain Cleaner (0.1 M NaOH) 13 1 M NaOH 1.0 x M 1 M HCl Answer the following questions: 1. What does [H + ] stand for? 2. If you know the concentration of [H + ] of a solution in decimal form, explain how you can determine its ph. 3. If you know the concentration of [H + ] of a solution in scientific notation, explain how you can determine its ph. 4. As the value of ph increases, what happens to the concentration of H +? 5. As the value of ph decreases, what happens to the concentration of H +? 6. Solution A has a ph of 5. Solution B has a ph of 9. a. What is the [H + ] of Solution A? Solution B? b. Identify the solutions as acidic or basic. c. Which solution has the greatest concentration of H +? How many times greater is the concentration of H +? 4

6 Part II: Looking at hydroxide, OH - Instructions: Imagine the following table contains results of a series of dilutions of HCl and NaOH. Additional information about the solutions (the poh) is included. Complete this table by adding in the missing values: HCl Solution NaOH Solution Well ph [H + ] [OH - ] poh A x 10-1 M 13 B x 10-2 M 1.0 x M 12 C x 10-3 M D x 10-4 M 1.0 x M 10 E x 10-5 M F x 10-6 M G x 10-7 M H x 10-7 M 1.0 x 10-7 M 7 I x 10-7 M 7 R x 10-7 M 1.0 x 10-7 M 7 Q x 10-7 M 7 P x 10-7 M O x 10-8 M N x 10-9 M 1.0 x 10-5 M 5 M x M L x M 3 K x M 1.0 x 10-2 M J x M 1.0 x 10-1 M 1 Answer the following questions: 1. What does [OH - ] stand for? 2. What can you say about the concentration of OH - in solutions with high acidity? 3. How is the value of the ph related to the value of the poh for each concentration? 4. If you know the value of the ph, how can you determine the value of the poh for the same solution? Making the connection: How are ph and poh related to each other mathematically? How are [H + ]and [OH - ] related to each other mathematically? 5

7 Name Per. ph Practice Worksheet Use the Guide to ph Calculations to do these problems. Given Unknown Acidic, Basic, or Neutral? (A/B/N) 1. ph = 7 poh = 2. poh = 12.5 ph = 3. [H + ] = 2.6 x 10-4 ph = 4. [H + ] = 1.0 x 10-8 ph = 5. [OH - ] = 1.3 x poh = 6. [OH - ] = 7.8 x 10-2 poh = 7. [OH - ] = 1.0 x [H + ] = 8. [OH - ] = 5.2 x 10-3 [H + ] = 9. [H + ] = 1.0 x 10-7 [OH - ] = 10. [H + ] = 9.1 x [OH - ] = 11. ph = 3.0 [H + ] = 12. ph = 11.6 [H + ] = 13. poh = 12.5 [OH - ] = 14. poh = 9.0 [OH - ] = 15. ph = 10.3 poh = 16. ph = 5.2 [H + ] = 17. poh = 14.0 ph = 18. poh = 4.4 [OH - ] = 6

8 Name Per. Practice Worksheet Neutralization Reactions I. Nomenclature Name the following: Write formulas for the following: 1. Al(NO 3 ) 3 4. potassium sulfate 2. HNO 3 5. lithium hydroxide 3. Ca(C 2 H 3 O 2 ) 2 6. calcium carbonate II. Neutralization Reactions: write the balanced equation for the reaction between the following acids and bases: 7. acetic acid and sodium hydroxide 8. hydrochloric acid and calcium hydroxide 9. phosphoric acid and magnesium hydroxide 10. carbonic acid and potassium hydroxide 11. sulfuric acid and ammonia (use NH 4 OH for ammonia; it s NH 3 + H 2 O) 12. nitric acid and lithium hydroxide 7

9 Titration Worksheet 1. What is the purpose of a titration? 2. Why do you need an indicator in a titration? 3. What is the difference between an endpoint and an equivalence point? 4. Why is it important not to overshoot the titration? Refer to your answer to #1. 5. Write the neutralization reaction between hydrochloric acid and potassium hydroxide. 6. What is the mole ratio of acid to base in the above reaction? 7. Write the neutralization reaction between nitric acid and calcium hydroxide. 8. What is the mole ratio of acid to base in the above reaction? 9. Write the neutralization reaction between sulfuric acid and lithium hydroxide. 10. What is the mole ratio of acid to base in the above reaction? 11. Calculate the molarity of an acetic acid solution if ml of this solution are needed to neutralize ml of M sodium hydroxide. IS THE EQUATION BALANCED? HC 2 H 3 O 2 (aq) + NaOH (aq) NaC 2 H 3 O 2 (aq) + H 2 O (l) ml of 0.60 M sodium hydroxide neutralized 20 ml of sulfuric acid. Determine the concentration of the acid. BALANCE THE EQUATION FIRST! H 2 SO 4 (aq) + NaOH Na 2 SO 4 (aq) + H 2 O (l) ml of 0.10 M nitric acid neutralized 40.0 ml of barium hydroxide. Determine the concentration of the base. BALANCE! HNO 3 (aq) + Ba(OH) 2 (aq) Ba(NO 3 ) 2 (aq) + H 2 O (l) 8