Question

How many moles of methane are in 7.31*10^25 molecules?

Answer 1

Answer:

121 mol CH₄

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

Organic

• Writing chemical compounds
• Writing organic structures
• Prefixes
• Alkanes, Alkenes, Alkynes

Atomic Structure

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

Explanation:

Step 1: Define

7.31 × 10²⁵ molecules CH₄

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

$\displaystyle 7.31 \cdot 10^{25} \ molecules \ CH_4(\frac{1 \ mol \ CH_4}{6.022 \cdot 10^{23} \ molecules \ CH_4} ) = 121.388 \ mol \ CH_4$

Step 4: Check

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

121.388 mol CH₄ ≈ 121 mol CH₄