Question

PLEASE DO ALL .

The solubility of silver bromate (mm( AgBrO3) = 235 g/mole) is determined to be 0.0072g/l

A.write the equation for the dissociation of silver bromate in water

B. Predict the sign for delta s for the reaction above

C. Determine the value for ksp for silver bromate

D. Determine the solubility in mg/l of silver bromate in .25 m sodium bromate solution

E. How would the solubility of this sale be affected by dissolving it in each of the following solutions ? (Increase, decrease . No change and why?

a. A solution with a low ph

b. .10m AgNO3

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Answer 1

solubility = 0.0072g/l

molar mass of silver bromate = 235 g/mol

solubilty = 0.0072 /235

S = 3.06 x 10^-5 M

A)

AgBrO3 (s) -----------------------> Ag+ (aq) + BrO3-(aq)

B)

delta = +ve . because solid converts into ions in the water that means randomness increases . so entropy increases

C)

AgBrO3 (s) -----------------------> Ag+ (aq) + BrO3-(aq)

Ksp = [Ag+][BrO3-]

Ksp = S x S

Ksp = (3.06 x 10^-5)^2

Ksp = 9.36 x 10^-10

D)

AgBrO3 (s) -----------------------> Ag+ (aq) + BrO3-(aq)

                                                  S                  S              ----------------------> in water

                                                  S                 S+ 0.25 ------------------------> in sodium bromate

Ksp = [Ag+][BrO3-]

Ksp = (S) (S+0.25)

compared to 0.25 , S can be neglected

Ksp = 0.25 x S

9.36 x 10^-10 = 0.25 x S

S = 3.74 x 10^-9 M

solubilty = 3.74 x 10^-9 mol / L

                = 3.74 x 10^-9 x 235 g/L

               = 8.8 x 10^-7 g / L

              = 0.00088 mg/L

E)

(a) at low pH solubiltity increases

AgBrO3 ----------------> Ag+ BrO3-

HA ----------------------> H+   + A-   (low pH means acidic medium HA is acid)

H+ react with BrO3- forms HBrO3 . so BrO3- concentration decrease from products. so solublity increases.

(b) in 0.1 M AgNO3

AgBrO3 (s) -----------------------> Ag+ (aq) + BrO3-(aq)

                                                  S                  S              ----------------------> in water

                                                  S                 S+ 0.1 ------------------------> in AgNO3

Ksp = [Ag+][BrO3-]

Ksp = (S) (S+0.1)

9.36 x 10^-10 = S x 0.1

S = 9.36 x 10^-9 M

solubilty = 9.36 x 10^-9 M

so in presence of AgNO3 solubilty increases.