Question

How many moles of PbNO3 are there in 4.5 g of PbNO3?

Answer 1

0.017 moles PbNO₃

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
• Moles

Stoichiometry

• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

[Given] 4.5 g PbNO₃

[Solve] moles PbNO₃

Step 2: Identify Conversions

[PT] Molar Mass of Pb - 207.2 g/mol

[PT] Molar Mass of N - 14.01 g/mol

[PT] Molar Mass of O - 16.00 g/mol

Molar Mass of PbNO₃ - 207.2 + 14.01 + 3(16.00) = 269.21 g/mol

Step 3: Convert

1. [DA] Set up:
   `\displaystyle 4.5 \ g \ PbNO_3((1 \ mol \ PbNO_3)/(269.21 \ g \ PbNO_3))`
2. [DA] Multiply/Divide [Cancel out units]:
   `\displaystyle 0.016716 \ moles \ PbNO_3`

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

0.016716 moles PbNO₃ ≈ 0.017 moles PbNO₃