Question

1. how many sodium atoms are there in 6.0 g of sodium nitride, na₃n? (molar mass of na₃n = 83.0 g/mol) a. 1.3 × 10²³ atoms b. 3.6 × 10²⁴ atoms c. 4.4 × 10²² atoms d. 2.1 × 10⁻¹ atoms e. 7.2 × 10⁻² atoms

Explanation:

Step1: Calculate moles of \( \text{Na}_3\text{N} \)

Moles = \( \frac{\text{mass}}{\text{molar mass}} \) = \( \frac{6.0\ \text{g}}{83.0\ \text{g/mol}} \approx 0.0723\ \text{mol} \)

Step2: Moles of Na atoms

In \( \text{Na}_3\text{N} \), 1 mol \( \text{Na}_3\text{N} \) has 3 mol Na. So moles of Na = \( 0.0723\ \text{mol} \times 3 = 0.2169\ \text{mol} \)

Step3: Number of Na atoms

Using Avogadro's number (\( 6.022 \times 10^{23}\ \text{atoms/mol} \)): Atoms = \( 0.2169\ \text{mol} \times 6.022 \times 10^{23}\ \text{atoms/mol} \approx 1.3 \times 10^{23}\ \text{atoms} \)

Answer:

A. \( 1.3 \times 10^{23} \) atoms