Question

42 mole Al= how many atoms?

Answer 1

Answer:

2.5 × 10²³ atoms Al

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

• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

42 mol Al

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

1. Set up:                               $\displaystyle 42 \ mol \ Al(\frac{6.022 \cdot 10^{23} \ atoms \ Al}{1 \ mol \ Al})$
2. Multiply/Divide:                 $\displaystyle 2.52924 \cdot 10^{25} \ atoms \ Al$

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

2.52924 × 10²³ atoms Al ≈ 2.5 × 10²³ atoms Al