5. Calculate the number of moles of potassium nitrate, KNO3, in a sample with a mass of 85.2 grams.

0.843 mol KNO₃

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

85.2 g KNO₃

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of N - 14.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of KNO₃ - 39.10 + 14.01 + 3(16.00) = 101.11 g/mol

Step 3: Convert

= 0.842647 mol KNO₃

Step 4: Check

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

0.842647 mol KNO₃ ≈ 0.843 mol KNO₃

a

explanation: