Question

Calculate the number of moles 2.5 g of calcium hydroxide.

Answer 1

0.044 mol CaOH

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
• Writing Compounds

Stoichiometry

• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

2.5 g CaOH

Step 2: Identify Conversions

[PT] Molar Mass of Ca - 40.08 g/mol

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

[PT] Molar Mass of H - 1.01 g/mol

Molar Mass of CaOH - 40.08 + 16.00 + 1.01 = 57.09 g/mol

Step 3: Convert

1. [DA] Set up:
   `\displaystyle 2.5 \ g \ CaOH((1 \ mol \ CaOH)/(57.09 \ g \ CaOH))`
2. [DA] Multiply/Divide [Cancel out units]:
   `\displaystyle 0.043791 \ mol \ CaOH`

Step 4: Check

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

0.043791 mol CaOH ≈ 0.044 mol CaOH