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Answer:
2.30 × 10⁻⁶ M
Explanation:
Step 1: Given data
Concentration of Mg²⁺ ([Mg²⁺]): 0.039 M
Solubility product constant of Mg(OH)₂ (Ksp): 2.06 × 10⁻¹³
Step 2: Write the reaction for the solution of Mg(OH)₂
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
Step 3: Calculate the minimum [OH⁻] required to trigger the precipitation of Mg²⁺ as Mg(OH)₂
We will use the following expression.
Ksp = 2.06 × 10⁻¹³ = [Mg²⁺] × [OH⁻]²
[OH⁻] = 2.30 × 10⁻⁶ M
The reagents for BaCO₃ is
BaO and CO₂
<em><u>Explanation</u></em>
Reagent is a substance that bring about a chemical reaction when added to a system.
Some reagent may be added to see if a reaction has occurred.
BaO and Co₂ are reagent since they react to produce BaCO₃ as below
BaO(s) + CO₂(g) → BaCO3(s)