Question

Which of the following statements is false?

AgCl is predicted to be more soluble in .10M HCN than in pure water (Kf of Ag(CN)₂ = 3x 10^²⁰)

Ag₂CO₃ is predicted to be more soluble in pure water than .10M HCL

A saturated aqueous solution of AgCl is predicted to exhibit an approx. neutral pH at 25 degrees Celsius.

AgCl is predicted to be more soluble in pure water than in .10 M HCl

Answer 1

1) AgCl is predicted to be more soluble in .10M HCN than in pure water (Kf of Ag(CN)₂ = 3x 10^²⁰)

true

Reason:

ksp of AgCl in water =1.8*10^-10

AgCl(s)Ag+(aq) + Cl- (aq)

Kf of Ag(CN)₂ = 3x 10^²⁰

AgCl +2HCN [Ag(CN)2 ]- + Cl- +2H+ so this complex is formed readily due to large kf value,so more soluble in HCN

2)Ag₂CO₃ is predicted to be more soluble in pure water than 0.10M HCL

False

In water,

ksp of Ag2CO3 in water =8.1*10^-12

Ag2CO3(s)2Ag+(aq) + CO3^2- (aq) [low solubility]

In HCl,

Ag2CO3 +2HCl2AgCl + H2CO3

ksp of AgCl>>ksp of Ag2CO3 So, Ag2CO3 reacts readily with HCl to form more soluble AgCl

3) A saturated aqueous solution of AgCl is predicted to exhibit an approx. neutral pH at 25 degrees Celsius.

true

AgCl(s)Ag+(aq) + Cl- (aq) ,ksp of AgCl in water =1.8*10^-10 (no H+ or OH- formed, so neutral solution formed on dissolution in water)

4) AgCl is predicted to be more soluble in pure water than in .10 M HCl

true

In HCl, due to the presence of common ion Cl- , the concentration of Cl- ion decreases in the solution ,thus AgCl precipitates out,thereby lowering its solubility further in water.