Answer:
9.9 × 10²⁰ molecules O₂
General Formulas and Concepts:
Math
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Chemistry
Atomic Structure
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K
Stoichiometry
- Using Dimensional Analysis
Explanation:
Step 1: Define
3.7 × 10⁻² L O₂ at STP
Step 2: Identify Conversions
[STP] 22.4 L/mol
Avogadro's Number
Step 3: Convert
- Set up: [tex]\displaystyle 3.7 \cdot 10^{-2} \ L \ O_2(\frac{1 \ mol \ O_2}{22.4 \ L \ O_2 \ at \ STP})(\frac{6.022 \cdot 10^{23} \ molecules \ O_2}{1 \ mol \ O_2})[/tex]
- Multiply/Divide: [tex]\displaystyle 9.94705 \cdot 10^{20} \ molecules \ O_2[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
9.94705 × 10²⁰ molecules O₂ ≈ 9.9 × 10²⁰ molecules O₂
