Question

How many molecules are in 50.0 grams of NaOH?

Answer 1

7.53 × 10²³ molecules NaOH

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

Step-by-step explanation:

Step 1: Define

50.0 g NaOH

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Na - 22.99 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H - 1.01 g/mol

Molar Mass of NaOH - 22.99 + 16.00 + 1.01 = 40 g/mol

Step 3: Convert

1. Set up:
   `\displaystyle 50.0 \ g \ NaOH((1 \ mol NaOH)/(40 \ g \ NaOH))((6.022 \cdot 10^(23) \ molecules \ NaOH)/(1 \ mol \ NaOH))`
2. Multiply:
   `\displaystyle 7.5275 \cdot 10^(23) \ molecules \ NaOH`

Step 4: Check

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

7.5275 × 10²³ molecules NaOH ≈ 7.53 × 10²³ molecules NaOH