Question

How many moles are in 0.821g of lead?

Answer 1

Answer:

3.96 × 10⁻³ mol Pb

Explanation:

Step 1: Find molar mass

Pb (Lead) - 207.2 g/mol

Step 2: Use Dimensional Analysis

$0.821 \hspace{2} g \hspace{2} Pb(\frac{1 \hspace{2} mol \hspace{2} Pb}{207.2 \hspace{2} g \hspace{2} Pb} )$ = 0.003962 mol Pb

Step 3: Simplify

We have 3 sig figs

0.003962 mol Pb ≈ 0.00396 mol Pb

0.00396 mol Pb = 3.96 × 10⁻³ mol Pb