Question

How many molecules OF2 would have a mass of .132 g

Answer 1

1.47 × 10²¹ molecules OF₂

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

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

0.132 g OF₂

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of O - 16.00 g/mol

Molar Mass of F - 19.00 g/mol

Molar Mass of OF₂ - 16.00 + 2(19.00) = 54.00 g/mol

Step 3: Convert

1. Set up:
   `\displaystyle 0.132 \ g \ OF_2((1 \ mol \ OF_2)/(54.00 \ g \ OF_2))((6.022 \cdot 10^(23) \ molecules \ OF_2)/(1 \ mol \ OF_2))`
2. Divide/Multiply:
   `\displaystyle 1.47204 \cdot 10^(21) \ molecules \ OF_2`

Step 4: Check

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

1.47204 × 10²¹ molecules OF₂ ≈ 1.47 × 10²¹ molecules OF₂