Question

How many moles of Na3N are there in 56.1 grams of Na3N?

a. 4660 moles

b. 2.46x10^-24 moles

c. 4.07x10^23 moles

d. 0.676 moles

Answer 1

D. 0.676 moles

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 Tables
• Compounds
• Moles

Stoichiometry

• Using Dimensional Analysis

Step-by-step explanation:

Step 1: Define

[Given] 56.1 g Na₃N

[Solve] moles Na₃N

Step 2: Identify Conversions

[PT] Molar Mass of Na - 22.99 g/mol

[PT] Molar Mass of N - 14.01 g/mol

Molar Mass of Na₃N - 3(22.99) + 14.01 = 82.98 g/mol

Step 3: Convert

1. [DA] Set up:
   `\displaystyle 56.1 \ g \ Na_3N((1 \ mol \ Na_3N)/(82.98 \ g \ Na_3N))`
2. [DA] Multiply/Divide [Cancel out units]:
   `\displaystyle 0.676067 \ mol \ Na_3N`

Step 4: Check

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

0.676067 mol Na₃N ≈ 0.676 mol Na₃N