Do Now - AP - Solubility Equilibrium

Match the following parts for the solubility of MgCl₂

K_sp = [Mg²⁺][Cl^-]²

• Concentration of Mg ion

• [Mg²⁺] or [Cl^-]/2

• molar solubility

• [Mg²⁺]

• Solubility Product Constant

• K_sp

Which one of the following is the solubility product constant for Mn(OH)₂?

• K_sp = [Mn²⁺][OH^-]²

• K_sp = [Mn²⁺][2 OH^-]²

• K_sp = [Mn²⁺]²[OH^-]²

• K_sp = [Mn²⁺]²[OH^-]

The concentration of OH– in a saturated solution of Mg(OH)₂ is 3.6 x 10^–4 M. The Ksp of Mg(OH)₂ is

• 1.3 x 10^–7

• 4.7 x 10^–11

• 3.6 x 10^–4

• 2.3 x 10^–11

The K_sp expression for a saturated solution of Ca₃(PO₄)₂ is

• K_sp = [Ca²⁺][PO₄^3-]

• K_sp = [3Ca²⁺][2PO₄^3-]

• K_sp = [Ca²⁺]³[PO₄^3-]²

• K_sp = [3Ca²⁺]³[2PO₄^3-]²

The correct mathematical expression for finding the solubility product constant of Sn(OH)₂ where X = molar solubility

• 2(X)³ = Ksp

• 108(X)⁵ = Ksp

• 4(X)³ = Ksp

• 8(X)³ = Ksp

Which of the following compounds would produce the least amount of ions in solution?

• Ag₃PO₄ Ksp = 1.8 x 10^–18

• Sn(OH)₂ Ksp = 5 x 10^–26

• CdS Ksp = 3.6 x 10^–29

• AgOH Ksp = 2 x 10^–33

Sodium chloride is added slowly to a solution that is 0.010 M in Cu+, Ag+, and Au+. The Ksp values for the chloride salts are (CuCl) 1.9 x 10^-7, (AgCl) 1,6 x 10^-10, and (AuCl) 2.0 x 10^-13, respectively. Which compound will precipitate first?

• CuCl(s)

• AgCl(s)

• AuCl(s)

• All will precipitate at the same time.

Answer explanation

If the Ksp for is AuCl <--> Au + Cl

is 2.0 x 10^-13 then the reverse of that reaction would be 1/2.0 x 10^-13 = 5 x 10¹² . This means that the reverse reaction is HEAVILY favored, so any addition of Cl would cause the reaction to shift to form AuCl

What is the Ksp expression for CaF₂?

• Ksp = [Ca²⁺][F^-]²

• Ksp = [Ca²⁺][F^-]

• Ksp = [Ca²⁺]²[F^-]²

• Ksp = [Ca²⁺]/[F^-]

If 30.0 mL of 5.0 x 10^-4 M Ca(NO₃)₂ are added to 70.0 mL of 2.0 x 10^-4 M NaF, will a precipitate occur? (Ksp of CaF₂ = 4.0 x 10^–11 and the final volume is 100.0 mL)

• No, because the ion product (Qsp) is greater than Ksp.

• Yes, because the ion product (Qsp) is less than Ksp.

• No, because the ion product (Qsp) is less than Ksp

• Yes, because the ion product is (Qsp) greater than Ksp.

How many moles of Ca(NO₃)₂ must be added to 1.0 L of a 0.100 M HF solution to begin precipitation of CaF₂ (s)? For CaF₂, Ksp = 4.0 x 10^–11.

• 5.8 x 10^–7

• 1.6 x 10^–9

• 7.0 x 10^–11

• 4.0 x 10^–9