Question

How many moles are in a 13.7g block of calcium?

Answer 1

Answer:

0.342 mol Ca

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

13.7 g Ca

Step 2: Identify Conversions

Molar Mass of Ca - 40.08 g/mol

Step 3: Convert

1. Set up:                               $\displaystyle 13.7 \ g \ Ca(\frac{1 \ mol \ Ca}{40.08 \ g \ Ca})$
2. Multiply/Divide:                 $\displaystyle 0.341816 \ mol \ Ca$

Step 4: Check

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

0.341816 mol Ca ≈ 0.342 mol Ca