Question

What is the mass in grams of 2.25 mol of the element iron, Fe?

Answer 1

Answer:

126 g Fe

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

Atomic Structure

• Reading a Periodic Table
• Using Dimensional Analysis

Explanation:

Step 1: Define

2.25 mol Fe

Step 2: Identify Conversions

Molar Mass of Fe - 55.85 g/mol

Step 3: Convert

1. Set up:                              $\displaystyle 2.25 \ mol \ Fe(\frac{55.85 \ g \ Fe}{1 \ mol \ Fe})$
2. Multiply:                            $\displaystyle 125.663 \ g \ Fe$

Step 4: Check

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

125.663 g Fe ≈ 126 g Fe