Question

Calculate the number of atoms in 0.25 moles of manganese?

Answer 1

Answer:

1.5 × 10²³ atoms Mn

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

• Using Dimensional Analysis
• Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Explanation:

Step 1: Define

0.25 mol Mn

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

1. Set up:                              $\displaystyle 0.25 \ mol \ Mn(\frac{6.022 \cdot 10^{23} \ atoms \ Mn}{1 \ mol \ Mn})$
2. Multiply:                            $\displaystyle 1.5055 \cdot 10^{23} \ atoms \ Mn$

Step 4: Check

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

1.5055 × 10²³ atoms Mn ≈ 1.5 × 10²³ atoms Mn