Question 1

Which of the following best explains why the solubility of Ag2CrO4 decreases sharply with increasing concentration of K2CrO4, as shown in the graph?

Accepted Answer

The common-ion effect reduces the solubility of Ag2CrO4 because $$CrO4^{2-} is a $$product ion.

Question 2

According to the graph, what is the effect of adding KNO3 to a solution of Ag2CrO4?

Accepted Answer

The solubility of Ag2CrO4 increases slightly due to the salt effect (diffuse ion effect).

Question 3

If the concentration of K2CrO4 is increased from 0.01 M to 0.05 M, what happens to the solubility of Ag2CrO4 and why?

Accepted Answer

The solubility decreases significantly because more $$CrO4^{2-}$$ shifts the equilibrium to the left.

Question 4

Which equation represents the solubility product expression for Ag2CrO4?

Accepted Answer

$$K_{sp} = [Ag^+]^2[$$CrO_4$$^{2-}]$$

Question 5

Why does the addition of KNO3 (a salt with no common ions) increase the solubility of Ag2CrO4 slightly?

Accepted Answer

The diffuse ion effect increases solubility by shielding ions and reducing their tendency to recombine.

Question 6

If the Ksp for Ag2CrO4 is $$1.1 	imes 10$$^{-12}$$, what is the solubility (s) of Ag2CrO4 in pure water in mol/L?

Accepted Answer

$$s = 6.5 	imes 10$$^{-5}$$

Question 7

A student adds K2CrO4 to a saturated solution of Ag2CrO4. What will happen to the concentration of Ag^+ ions?

Accepted Answer

The concentration of Ag^+ will decrease due to the common-ion effect.

Question 8

Which of the following best describes the difference between the common-ion effect and the salt effect as illustrated in the graph?

Accepted Answer

The common-ion effect decreases solubility, while the salt effect slightly increases solubility.

Question 9

If the initial concentrations of Ag^+ and $$CrO4^{2-} in a $$solution are such that $$Q \u003e K_{sp}$$ for Ag2CrO4, what will occur?

Accepted Answer

Ag2CrO4 will precipitate until equilibrium is reached.

Question 10

Which real-world scenario best illustrates the importance of the common-ion effect in water treatment?

Accepted Answer

Adding lime (Ca(OH)2) to precipitate phosphate ions from wastewater by decreasing their solubility.

Question 11

If you want to maximize the solubility of Ag2CrO4 in solution, which of the following should you avoid adding?

Accepted Answer

K2CrO4

Question 12

Which of the following statements is true regarding the units of Ksp?

Accepted Answer

Ksp is unitless because it is an equilibrium constant.

Solubility Product Constant (Ksp) and Factors Affecting Solubility

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