Question

A sample of iron (III) chloride has a mass of 26.29g. How many moles would this be?

Answer 1

Answer:

0.1621 mol FeCl₃

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

Compounds

• Determining compound formulas

Atomic Structure

• Reading a Periodic Table
• Using Dimensional Analysis

Explanation:

Step 1: Define

26.29 g FeCl₃ (iron (III) chloride)

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: Convert

1. Set up:                              $\displaystyle 26.29 \ g \ FeCl_3(\frac{1 \ mol \ FeCl_3}{162.2 \ g \ FeCl_3})$
2. Multiply:                            $\displaystyle 0.162084 \ moles \ FeCl_3$

Step 4: Check

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

0.162084 mol FeCl₃ ≈ 0.1621 mol FeCl₃