Question

1. Calculate the mass of iron needed to make 16.25g of iron chloride (3
marks)


2Fe + 3Cl2 → 2FeCl3​

Answer 1

Answer:

5.595 g Fe

General Formulas and Concepts:

Chemistry - Stoichiometry

• Reading a Periodic Table
• Using Dimensional Analysis

Explanation:

Step 1: Define

16.25 g FeCl₃ (Iron III Chloride)

RxN:   2Fe + 3Cl₂ → 2FeCl₃

Step 2: Identify Conversions

Molar Mass of Fe - 55.85 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of FeCl₃ - 55.85 + 3(35.45) = 162.2 g/mol

Step 3: Stoichiometry

$16.25 \ g \ FeCl_3(\frac{1 \ mol \ FeCl_3}{162.2 \ g \ FeCl_3} )(\frac{2 \ mol \ Fe}{2 \ mol FeCl_3} )(\frac{55.85 \ g \ Fe}{1 \ mol \ Fe} )$ = 5.59533 g Fe

Step 4: Check

We are given 4 sig figs. Follow sig fig rules and round.

5.59533 g Fe ≈ 5.595 g Fe