CaSO$_4$, $K_{sp} = 7.1 \times 10^{-5}$

$K_{sp} = 27s^4 = 27 \times (1.8 \times 10^{-4})^4$

Question 1

Which of the following statements best describes the solubility product constant ($K_{sp}$)?

Accepted Answer

$K_{sp}$ is the equilibrium constant that deals with the solubility of ionic solids in water.

Question 2

Given the following $K_{sp}$ values, which compound is the most soluble in water?

Accepted Answer

CaSO$_4$, $K_{sp} = 7.1 	imes 10^{-5}$

Question 3

Which of the following is ignored when writing the equilibrium expression for a solubility product ($K_{sp}$)?

Accepted Answer

Concentration of solids

Question 4

What is the correct equilibrium expression for the dissolution of calcium nitrate, Ca(NO$_3$)$_2$ (s), in water?

Accepted Answer

$K_{sp} = [Ca^{2+}][NO_3^-]^2$

Question 5

If the solubility of Ag$_3$PO$_4$ is $1.8 	imes 10^{-4}$ M at 25°C, what is the $K_{sp}$ value?

Accepted Answer

$K_{sp} = 27s^4 = 27 	imes (1.8 	imes 10^{-4})^4$

Question 6

Which of the following best explains why $K_{sp}$ values are used to compare the solubility of different ionic compounds?

Accepted Answer

$K_{sp}$ values account for the stoichiometry of the ions produced in solution.

Question 7

The $K_{sp}$ for strontium fluoride, SrF$_2$, is $7.9 	imes 10^{-5}$ at 25°C. What is the correct equilibrium expression?

Accepted Answer

$K_{sp} = [Sr^{2+}][F^-]^2$

Question 8

A student is asked to calculate the solubility of SrF$_2$ in mol/L given $K_{sp} = 7.9 	imes 10^{-5}$. Which equation should they use?

Accepted Answer

$K_{sp} = s 	imes (2s)^2$

Question 9

If the measured solubility of Mn(OH)$_4$ is $3.4 	imes 10^{-4}$ M at 25°C, what is the $K_{sp}$ expression for this compound?

Accepted Answer

$K_{sp} = [Mn^{4+}][OH^-]^4$

Question 10

Which of the following best describes the process of dissolution for an ionic solid in water?

Accepted Answer

The solid dissociates into its constituent ions, which become surrounded by water molecules.

Question 11

A solution is saturated with respect to CaSO$_4$. What will happen if more CaSO$_4$ is added?

Accepted Answer

The added CaSO$_4$ will remain undissolved at the bottom of the container.

Question 12

Which of the following is a correct step in calculating the $K_{sp}$ from the solubility of an ionic compound?

Accepted Answer

Write the equilibrium equation by breaking up the ionic solid into its aqueous ions.

Question 13

If the $K_{sp}$ of a salt is very small, what does this indicate about its solubility?

Accepted Answer

The salt is only slightly soluble in water.

Question 14

Which of the following would increase the solubility of a sparingly soluble salt in water?

Accepted Answer

Removing one of the product ions from the solution as it forms.

Question 15

A chemist needs to determine the $K_{sp}$ of a new compound. Which of the following data is most directly required?

Accepted Answer

The molar solubility of the compound in water.

Question 16

Which of the following is the correct $K_{sp}$ expression for barium nitride, Ba$_3$N$_2$?

Accepted Answer

$K_{sp} = [Ba^{2+}]^3[N^{3-}]^2$

Solubility Product Constant (Ksp) and Solubility Equilibria

Study Guide - Practice Questions