Answer:
2.29x10⁻¹² is Ksp of the salt
Explanation:
The Ksp of the metal hydroxide is:
M(OH)₂(s) ⇄ M²⁺ + 2OH⁻
Ksp = [M²⁺] [OH⁻]²
As you can see in the reaction, 2 moles of OH⁻ are produced per mole of M²⁺. It is possible to find [OH⁻] with pH, thus:
pOH = 14- pH
pOH = 14 - 10.22
pOH = 3.78
pOH = -log[OH⁻]
<em>1.66x10⁻⁴ = [OH⁻]</em>
And [M²⁺] is the half of [OH⁻], <em>[M²⁺] = 8.30x10⁻⁵</em>
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Replacing in Ksp formula:
Ksp = [8.30x10⁻⁵] [1.66x10⁻⁴]²
Ksp = 2.29x10⁻¹² is Ksp of the salt
1,000 mL/ 1 L
Your last option
Significant figures are the digits that come after the first non-zero digit. The second value has 11 significant figures and is therefore the correct answer. However, the fourth answer has 4 significant figures and would also be a correct answer. So I don’t know if perhaps there has been a typo or a mistake in the question but with what you have provided here, both these answer have more than 2 significant figures.