Question

CH4 + 202 → CO2 + 2H2O
How many moles O2 needed to produce 4 moles of H2O?

Answer 1

Answer:

4 mol O₂

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

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

[RxN - Balanced]   CH₄ + 2O₂ → CO₂ + 2H₂O

[Given]   4 mol H₂O

[Solve]   x mol O₂

Step 2: Identify Conversions

[RxN] 2 mol H₂O → 2 mol O₂

Step 3: Stoichiometry

1. Set up conversion:                    $\displaystyle 4 \ mol \ H_2O(\frac{2 \ mol \ O_2}{2 \ mol \ H_2O})$
2. Multiply/Divide:                          $\displaystyle 4 \ mol \ O_2$

Answer 2

Moles of O₂= 4

Further explanation

Given

Reaction

CH₄ + 20₂ → CO₂ + 2H₂O

4 moles of H₂O

Required

Moles of O₂

Solution

In a chemical equation, the reaction coefficient shows the mole ratio of the compounds involved in the reaction, reactants or products

From the equation, mol ratio of H₂O  : O₂ = 2 : 2, so moles O₂ :

= 2/2 x moles H₂O

= 2/2 x 24

= 4 moles