Question

Mg(s) + HCl(aq) −→ MgCl2(aq) + H2(g).

What mass of HCl is consumed by the reaction of 2.28 mol of magnesium?
Answer in units of g

Answer 1

166 g HCl

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Chemistry

Stoichiometry

• Reading a Periodic Table
• Balancing Equations
• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

[RxN - Unbalanced] Mg (s) + HCl (aq) → MgCl₂ (aq) + H₂ (g)

[RxN - Balanced] Mg (s) + 2HCl (aq) → MgCl₂ (aq) + H₂ (g)

[Given] 2.28 mol Mg (s)

Step 2: Identify Conversions

[RxN] 1 mol Mg = 2 mol HCl

Molar Mass of H - 1.01 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of HCl - 1.01 + 35.45 = 36.46 g/mol

Step 3: Stoichiometry

1. Set up:
   `\displaystyle 2.28 \ mol \ Mg((2 \ mol \ HCl)/(1 \ mol \ Mg))((36.46 \ g \ HCl)/(1 \ mol \ HCl))`
2. Multiply:
   `\displaystyle 166.258 \ g \ HCl`

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

166.258 g HCl ≈ 166 g HCl