Question

please answer both question and box the answers

QUESTION 2 What is the H30 ion concentration in an aqueous solution having an OH concentration of 1.0 x 10 M at 25 °C? а. 1.0x 102 M b. 13x 102 M C. 12x 10 2 M d. 12x 10 12 M 1.0x 10 12 M

Answer 1

2)

use:

[H3O+] = Kw/[OH-]

Kw is dissociation constant of water whose value is 1.0*10^-14 at 25 oC

[H3O+] = (1.0*10^-14)/[OH-]

[H3O+] = (1.0*10^-14)/1*10^-2

[H3O+] = 1.0*10^-12 M

Answer: e

3)

At equilibrium:

SrCO3 <----> Sr2+ + CO32-

   s s

Ksp = [Sr2+][CO32-]

9.3*10^-10=(s)*(s)

9.3*10^-10= 1(s)^2

s = 3.05*10^-5 M

At equilibrium:

AgCl <----> Ag+ + Cl-

   s s

Ksp = [Ag+][Cl-]

1.8*10^-10=(s)*(s)

1.8*10^-10= 1(s)^2

s = 1.342*10^-5 M

At equilibrium:

BaCrO4 <----> Ba2+ + CrO42-

   s s

Ksp = [Ba2+][CrO42-]

1.2*10^-10=(s)*(s)

1.2*10^-10= 1(s)^2

s = 1.095*10^-5 M

At equilibrium:

MnS <----> Mn2+ + S2-

   s s

Ksp = [Mn2+][S2-]

2.5*10^-10=(s)*(s)

2.5*10^-10= 1(s)^2

s = 1.581*10^-5 M

At equilibrium:

BaSO4 <----> Ba2+ + SO42-

   s s

Ksp = [Ba2+][SO42-]

1.1*10^-10=(s)*(s)

1.1*10^-10= 1(s)^2

s = 1.049*10^-5 M

The compound with minimum solubility is:

BaSO4

Answer: e