Question

How many moles of Al would be produced from 20 moles of Al2O3? 2Al2O3 -> 4A1 + 302

Answer 1

Answer:

$\displaystyle 40 \ mol \ Al$

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

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

[RxN - Balanced] 2Al₂O₃ → 4Al + 3O₂

[Given] 20 mol Al₂O₃

Step 2: Identify Conversions

[RxN] 2 mol Al₂O₃ → 4 mol Al

Step 3: Stoich

1. [DA] Set up:                                                                                                     $\displaystyle 20 \ mol \ Al_2O_3(\frac{4 \ mol \ Al}{2 \ mol \ Al_2O_3})$
2. [DA] Multiply/Divide [Cancel out units]:                                                         $\displaystyle 40 \ mol \ Al$

Step 4:Check

Follow sig fig rules and round. We are given 1 sig fig.

Since our final answer already has 1 sig fig, there is no need to round.