(b) What volume of HCl is needed to neutralize 2.87 g of Mg(OH)₂?

Verified step by step guidance

1. Identify the balanced chemical equation for the reaction: \[ \text{Mg(OH)}_2 + 2\text{HCl} \rightarrow \text{MgCl}_2 + 2\text{H}_2\text{O} \]
2. Calculate the molar mass of \( \text{Mg(OH)}_2 \) using the periodic table: \( \text{Mg} = 24.31 \text{ g/mol}, \text{O} = 16.00 \text{ g/mol}, \text{H} = 1.01 \text{ g/mol} \).
3. Convert the mass of \( \text{Mg(OH)}_2 \) to moles using its molar mass: \[ \text{moles of Mg(OH)}_2 = \frac{2.87 \text{ g}}{\text{molar mass of Mg(OH)}_2} \]
4. Use the stoichiometry from the balanced equation to find the moles of \( \text{HCl} \) needed: \[ \text{moles of HCl} = 2 \times \text{moles of Mg(OH)}_2 \]
5. Calculate the volume of \( \text{HCl} \) solution required using its concentration: \[ \text{Volume of HCl} = \frac{\text{moles of HCl}}{\text{concentration of HCl}} \]

Key Concepts

Neutralization Reaction

A neutralization reaction occurs when an acid reacts with a base to produce water and a salt. In this case, hydrochloric acid (HCl) reacts with magnesium hydroxide (Mg(OH)2) to form magnesium chloride (MgCl2) and water. Understanding this reaction is crucial for determining the stoichiometry involved in calculating the required volume of HCl.

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on balanced chemical equations. It allows us to determine the mole ratios of the substances involved. For this question, knowing the molar mass of Mg(OH)2 and the balanced equation for its reaction with HCl will enable us to find out how much HCl is needed to neutralize a specific mass of Mg(OH)2.

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is essential for calculating the volume of HCl required for neutralization. By knowing the molarity of the HCl solution, we can use the stoichiometric relationships from the balanced equation to find the exact volume needed to react with the given mass of Mg(OH)2.