Question

Calculate the mass of 3.5 moles of H2O

Answer 1

Answer:

63 g H₂O

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

Stoichiometry

• Using Dimensional Analysis

Explanation:

Step 1: Define

3.5 mol H₂O

Step 2: Identify Conversions

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol

Step 3: Convert

1. Set up:                               $\displaystyle 3.5 \ mol \ H_2O(\frac{18.02 \ g \ H_2O}{1 \ mol \ H_2O})$
2. Divide/Multiply:                 $\displaystyle 63.07 \ g \ H_2O$

Step 4: Check

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

63.07 g H₂O ≈ 63 g H₂O