Question

How many atoms are in a 158.69 g sample of nickel?

Answer 1

Answer:

1.6283 × 10²⁴ atoms Ni

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

Stoichiometry

• Use Dimensional Analysis

Explanation:

Step 1: Define

158.69 g Ni

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Ni - 58.69 g/mol

Step 3: Convert

1. Set up:                      $\displaystyle 158.69 \ g \ Ni(\frac{1 \ mol \ Ni}{58.69 \ g \ Ni})(\frac{6.022 \cdot 10^{23} \ atoms \ Ni}{1 \ mol \ Ni})$
2. Multiply/Divide:        $\displaystyle 1.62827 \cdot 10^{24} \ atoms \ Ni$

Step 4: Check

Follow sig fig rules and round. We are given 5 sig figs.

1.62827 × 10²⁴ atoms Ni ≈ 1.6283 × 10²⁴ atoms Ni