1. © 2012 Pearson Education, Inc. MAYHAN Ch. 14 Review ws

2. © 2012 Pearson Education, Inc. I can… Distinguish an acid from a base by its properties. Explain the difference theories of acid and base behavior of an Arrhenius A/B, Bronsted-Lowry A/B and Lewis A/B. Use the concentrations of acids and bases to calculate pH and pOH. Explain how strong acid and strong base ionize in water and how weak acids and weak based dissociate. Use Ka and concentrations weak acids to find pH and likewise with bases (Kb). Explain how the weak acid/base concentrations affect the magnitude of Ka or Kb. State how salt solutions can affect the properties of an acid or base. Explain the factors that make a strong acid “strong”. MAYHAN

3. © 2012 Pearson Education, Inc. MAYHAN 1.a. Write the formula AND NAME of the 6 strong acids b. Write the formula AND NAMES of the 6 strong bases. H 2 SO 4 sulfuric acid HNO 3 nitric acid HClO 4 perchloric acid HCl hydrochloric acid HBr hydrobromic acid HI hydroiodic acid NaOH sodium hydroxide KOH potassium hydroxide RbOH rubidium hydroxide Ca(OH) 2 Calcium hydroxide Sr(OH) 2 Strontium hydroxide Ba(OH) 2 Barium hydroxide

4. © 2012 Pearson Education, Inc. 2. Give the conjugate base for each of the following Brønsted-Lowry acids 1.HI 2.NH 4 + 3.H 2 CO 3 4. HNO 3 I-I- NH 3 HCO 3 - NO 3 -

5. © 2012 Pearson Education, Inc. 2. Give the conjugate acid for each of the following Brønsted-Lowry bases. 1.CN – 2.O 2– 3.CH 3 COO – 4. NH 3 HCN OH - CH 3 COOH NH 4 +

6. © 2012 Pearson Education, Inc. 3. Complete the Brønsted-Lowry equilibria, label the components acid or base, and pair up the conjugate acid-base pairs: a.HSO 4 - + H 2 O  SO 4 -2 + H 3 O + b.NH 3 + H 2 O  NH 4 + + OH - c.CN - + H 2 O  HCN + OH - d. HClO 4 + H 2 O  H 3 O + + ClO 4 - Acid Base C-Base C-Acid Base Acid C-Acid C-Base Base Acid C-Acid C-Base Acid Base C-Acid C-base MAYHAN

7. © 2012 Pearson Education, Inc. 4.What is the pH of a.0.0010 M HCl solution? b.0.15 M KOH solution? c.1 x 10 -8 M HNO 3 solution? pH = 3 pH = 13 pH = 8 MAYHAN

8. © 2012 Pearson Education, Inc. [H + ][OH - ]pHpOHacidic or basic 2.0 x 10 -5 6.25 5.6 x 10 -2 9.20 8.7 x 10 -10 5.0 x10 -10 9.30 4.70 Acidic 5.6 x10 -7 1.8 x10 -8 7.75 Acidic 1.8 x10 -13 12.71.3Basic 6.3 x10 -10 1.6 x10 -5 4.80 Acidic 1.1 x10 -5 4.949.1 Basic MAYHAN

9. © 2012 Pearson Education, Inc. 6. What is the pH of a solution that contains 2.60 grams of NaOH in 250 mL of aqueous solution? 2.60 g /39.9g = 0.065 mole 0.065 mole/0.250L = 0.261 M 1.0 x 10 -14 /0.261 =3.83 x 10 -14 pH is = 13 MAYHAN

10. © 2012 Pearson Education, Inc. 7. If the pH of a sample of rainwater is 4.62, what is the hydrogen ion concentration [H + ] and the hydroxide ion concentration [OH - ] in the rainwater? -4.62 antilog = 2.4 x 10 -5 M of [H+] 1.0 x 10 -14 / 2.4 x 10 -5 M =4.2 x 10 -10 MAYHAN

11. © 2012 Pearson Education, Inc. 8. A 0.12 M solution of an unknown weak acid has a pH of 4.26 at 25°C. What is the hydrogen ion concentration in the solution and what is the value of its K a ? -4.26 antilog = 5.5 x 10 -5 M of [H+] [5.5 x 10 -5 ] 2 / 0.12M = Ka= 2.5 x 10 -8 MAYHAN

12. © 2012 Pearson Education, Inc. 9. Hydroxylamine is a weak base with a K b = 6.6 x 10 -9. What is the pH of a 0.36 M solution of hydroxylamine in water at 25°C? (6.6 x 10 -9 )(0.36)= x 2 2.376 x 10 -9 = x 2 [HB] [OH  ] [B-] K b = [x] 2 [0.36] 6.6 x 10 -9 = √2.376 x 10 -9 = √ x 2 4.87x 10 -5 = [OH-]pOH = 4.31 pH = 14.00 - 4.31 pH = 9.69 MAYHAN

13. © 2012 Pearson Education, Inc. 10. Cyanic acid HOCN has a K a = 3.5 x 10 -4, what is the K b for the cyanate ion OCN - ? 1.0 x 10 -14 / 3.5 x 10 -4 = Kb 2.86 x 10 -11 = Kb KwKaKwKa K b = MAYHAN

14. © 2012 Pearson Education, Inc. 11.Suppose you dissolved benzoic acid in water to make a 0.15 M solution. K a for benzoic acid= 6.3 x 10 -5 at 25°C. What is pH: = 6.3 x 10 -5 [H+] [OH  ] [HA] K a = (6.3 x 10 -5 )(0.15) = x 2 √9.45 x 10 -6 = √ x 2 3.04 x 10 -3 = [H+] -log 3.04 x 10 -3 = 2.5 MAYHAN [x] [0.15] K a =

15. © 2012 Pearson Education, Inc. a.sodium nitrate NaNO 3 12. For each of the following salts, predict whether an aqueous solution would be acidic, basic, or neutral. Provide the equation for hydrolysis for these salts and the Ka or Ka expression (if applicable). Strong base/strong acid- neutral MAYHAN NaNO 3  NaOH + HNO 3 Ka or Kb not applicable

16. © 2012 Pearson Education, Inc. MAYHAN b. ammonium iodide c. sodium bicarbonate Weak base/strong acid- acidic salts NH 4 I  NH 4 OH + HI [H 3 O + ] [NH 3 ] [NH 4 + ] K a = NH 4 +  NH 3 + H 3 O + Strong base/weak acid- basic salts NaHCO 3  NaOH + H 2 CO 3 [OH - ] [H 2 CO 3 ] [HCO 3 - ] K b = HCO 3 -  OH - + H 2 CO 3

17. © 2012 Pearson Education, Inc. MAYHAN d. potassium acetate e.ammonium nitrate f. potassium chloride Strong base/weak acid- basic salts KC 2 H 3 O 2  KOH + HC 2 H 3 O 2 [OH - ] [C 2 H 3 O 2 - ] [HC 2 H 3 O 2 ] K b = C 2 H 3 O 2 -  OH - + HC 2 H 3 O 2 Weak base/strong acid- acidic salts NH 4 NO 3  NH 4 OH + HNO 3 [H 3 O + ] [NH 3 ] [NH 4 + ] K a = NH 4 +  NH 3 + H 3 O + KCl  KOH + HCl Ka or Kb not applicable