Question

Which equation shows how to calculate how many grams (g) of KOH would
be needed to fully react with 4 mol Mg(OH)2? The balanced reaction is:
MgCl2 + 2KOH → Mg(OH)2 + 2KCI

Answer 1

Answer:

A.

General Formulas and Concepts:

Chemistry - Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

Given:   4 mol Mg(OH)₂

RxN:   MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar mass of O - 16.00 g/mol

Molar mass of H - 1.01 g/mol

Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol

Step 3: Stoichiometry

$4 \ mol \ Mg(OH)_2(\frac{2 \ mol \ KOH}{1 \ mol \ Mg(OH)_2} )(\frac{56.11 \ g \ KOH}{1 \ mol \ KOH} )$