Question

How many molecules are contained in 103.4g of sulfuric acid?

Answer 1

Answer:

1.827 × 10²⁴ molecules H₂S

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

Compounds

• Writing Compounds
• Acids/Bases

Atomic Structure

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

Explanation:

Step 1: Define

103.4 g H₂S (Sulfuric Acid)

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of H - 1.01 g/mol

Molar Mass of S - 32.07 g/mol

Molar Mass of H₂S - 2(1.01) + 32.07 = 34.09 g/mol

Step 3: Convert

1. Set up:                              $\displaystyle 103.4 \ g \ H_2S(\frac{1 \ mol \ H_2S}{34.09 \ g \ H_2S})(\frac{6.022 \cdot 10^{23} \ molecules \ H_2S}{1 \ mol \ H_2S})$
2. Multiply:                                                                                                            $\displaystyle 1.82656 \cdot 10^{24} \ molecules \ H_2S$

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

1.82656 × 10²⁴ molecules H₂S ≈ 1.827 × 10²⁴ molecules H₂S