Question

Answer the following questions about the solubility of CoCO3(s). The value of Ksp for CoCO3(s) is 1.0 × 10^−10.

A. Calculate the value of [Co2+] in a saturated solution of CoCO3 in distilled water.


B. If 0.10 M of Co2+ is already present in distilled water, calculate the molar solubility of CoCO3(s).


C. Explain why CoCO3 is less soluble in distilled water that already contains Co2+

Answer 1

Attached picture.

Step-by-step explanation:

(1) Ksp equals the product of [Co 2+][CO3 2-]. CoCO3 is excluded from the equilibrium expression because it is a pure solid. The mole ratio of Co 2+ and CO3 2- is 1:1 so their molar solubilities are the same.

(2) There is an initial concentration of 0.10 M Co 2+ so write that in the "I" row for Co 2+ on the ICE table. When you find the zeros of the quadratic when solving for "s", take the positive value rather than the negative value because concentration cannot be negative.

(3) Extra products will cause the equilibrium to consume products and form reactants. So the reverse reaction will occur faster than the forward reaction. More products mean an increased Q value compared to K, since the numerator of
`K = ([products])/([reactants])` increases.