Question

1. In which solution will aluminum hydroxide, Al(OH)3, be least soluble? The solutions are similar except that they have the following pH values: Hint: Common ion effect. Which two ions dictate acidity and basicity?

a. 3    b. 7    c. 9    d. 11

2. Potassium perchlorate has a solubility product constant of 10^-2. Which is true about the following solution of KClO₄: [K+] = 0.01 M, [ClO4 −] = 0.01 M

a. Ksp < Q and no precipitation occurs

b. Ksp > Q and no precipitation occurs

c. Ksp < Q and precipitation occurs

d. Ksp > Q and precipitation occurs

e. Ksp = Q and no precipitation occurs

3. The Ksp of silver chloride is 1.6 * 10^-6 and that of silver iodide is 1.5 * 10^-16. A solution contains 1.0 × 10^–2 mol of KI and 0.10 mol of KCl per liter. AgNO3 is gradually added to this solution. Which forms first, solid AgI or solid AgCl? And has any formed when the NO^3- concentration has reached 10^-12?   Hint: From the Ksp values, we can see that one of these is MUCH more soluble than the other.

a. AgCl, yes

b. AgCl, no

c. AgI, yes    

d. AgI, no

4. Which of the following carbonates will form first?.

(a) MgCO3 Ksp = 3.5 × 10⁻⁸

(b) CaCO3 Ksp = 4.2 × 10⁻⁷

(c) SrCO3 Ksp = 3.9 × 10⁻⁹

(d) BaCO3 Ksp = 4.4 × 10⁻⁵

(e) MnCO3 Ksp = 5.1 × 10⁻⁹

5. Which of the following carbonates will form last?

(a) MgCO3 Ksp = 3.5 × 10⁻⁸

(b) CaCO3 Ksp = 4.2 × 10⁻⁷

(c) SrCO3 Ksp = 3.9 × 10⁻⁹

(d) BaCO3 Ksp = 4.4 × 10⁻⁵

(e) MnCO3 Ksp = 5.1 × 10⁻⁹

6. Addition of NH3 to a saturated solution of Cu(OH)2 in contact with solid Cu(OH)2   ________ the solubility of the solid because of a Lewis acid – base reaction between ammonia and ___________.

a. increases, Cu²⁺

b. increases, OH-

c. decreases, Cu²⁺

d. decreases, OH-

7. Identify the Lewis acid and the Lewis base (hint- it would probably help to write Lewis dot structures):

CO₂ + OH− ⟶ HCO₃−

a. acid: carbon dioxide, base: hydroxide

b. acid: hydroxide, base: carbon dioxide

c. acid: hydrogen carbonate, base: carbon dioxide

d. acid: hydroxide, base: hydrogen carbonate

8. Identify the Lewis acid and the Lewis base (hint- it would probably help to write Lewis dot structures):

O²⁻ + SO₃ ⟶ (SO₄) ²⁻

a. acid: oxygen, base: sulfur trioxide

b. acid: sulfur trioxide, base: oxygen

c. acid: sulfate, base: oxygen

d. acid: oxygen, base: sulfate

9. Boric acid, H3BO3, is not a Brønsted-Lowry acid but a Lewis acid. Think of it as B(OH)₃ with three OH bonded to a central B.

Write an equation for its reaction with water and predict the shape of the anion thus formed.

a. H3BO3 triangular planar

b. H4BO4 triangular planar

c. H4BO3 tetrahedral

d. H4BO4 tetrahedral

Answer 1

1) Alloh A13T + 300- so, if on- is high in solution due to common ion effect solubility is low. I on is maximum at pH = 11 so Answe = (d) 3 Ka= [k] [lo] = 0.01 0.0l = 104 (5) So Ka < kap, no pu o p tohon occu Agle and Ag I have same number of cations and anions so we can comme directly from ksp values, Lowe kop will precipitate first so, solid Ag I will form just o kop = [ce-70 Agr] = 10-18 10-12 = 10-3 No, (Ag +) = (NO)=0-27 Kop = [-] [Ag] = 102 x 10-12 = 10-14 Yes - Ans = (c) Ag I, yy 14 & 5) We will compare Kups directly because number of cations and anions are same. So Lowesti Kup precipitate, first & highest ka precipitate last 4) (C) Sr LOz (5) BaCO3 679 increases, Cu2+ Culon) =200'+ Cu²+ 4NM [lu (NH) ft . con (as au'd = co, bare = OH (Lewis acid) (Lewis bax) I 9 M₂ Botho HyBou +H+ tetrahedral Give electros B = 1 1 1 25 2P - co ó I Give electron con (as auid=co. take electrons B) oʻī + eas=0 Pse 117 o (lewis base) take electross Clewis bas) Clewis acid) (b) acid=50z , bass = 02- (d) My Boy", tetrahedral