Answer:
a.
silver iodide BC
manganese(II) hydroxide A
b.
silver iodide Ksp = S²
manganese(II) hydroxide Ksp = 4S³
Explanation:
Ksp (Solubility products) are the equilibrium constants for poorly soluble compounds. <em>As every equilibrium constant, it is formed by the product of the products raised to their stoichiometric coefficients divided by the product of reactants raised to their stoichiometric coefficients.</em> We only include in the constant <em>gases</em> and <em>aqueous species</em>. So, to solve this task, we need to write each reaction and its Ksp.
1. Silver Iodide
AgI(s) ⇄ Ag⁺(aq) + I⁻(aq)
When AgI is put in water, the concentration of Ag⁺ and I⁻ that actually dissolve is known as solubility (S). So the concentration of both Ag⁺ and I⁻ would be S.
AgI(s) ⇄ Ag⁺(aq) + I⁻(aq)
S S
We can replace this in the Ksp expression:
Ksp = [Ag⁺].[I⁻] = S.S = S²
We can follow the same steps to find out the relationship between Ksp and S for each compound.
2. Mn(OH)₂(s) ⇄ Mn²⁺(aq) + 2OH⁻(aq)
S 2S
In this case, the concentration of OH⁻ is 2S because 2 moles are produced along with 1 mole of Mn²⁺.
Ksp = [Mn²⁺].[OH⁻]² = S.(2S)² = 4S³
A. Fe(OH)₂(s) ⇄ Fe²⁺(aq) + 2OH⁻(aq)
S 2S
Ksp = [Fe²⁺].[OH⁻]² = S.(2S)² = 4S³
B. CaSO₃(s) ⇄ Ca²⁺(aq) + SO₃²⁻(aq)
S S
Ksp = [Ca²⁺].[SO₃²⁻] = S.S = S²
C. NiCO₃(s) ⇄ Ni²⁺(aq) + CO₃²⁻(aq)
S S
Ksp = [Ni²⁺].[CO₃²⁻] = S.S = S²
D. Ba₃(PO₄)₂(s) ⇄ 3 Ba²⁺(aq) + 2 PO₄³⁻(aq)
3S 2S
Ksp = [Ba²⁺]³.[PO₄³⁻]²= (3S)³.(2S)²= 108S⁵
a. The salts that can be compared using the same Ksp expressions are:
silver iodide BC
manganese(II) hydroxide A
b.
silver iodide Ksp = S²
manganese(II) hydroxide Ksp = 4S³
