Question

how many moles of pb(no₃)₂ are required to generate 12 moles al(no₃)₃?
3pb(no₃)₂ + 2alcl₃ → 3pbcl₂ + 2al(no₃)₃
? mol pb(no₃)₂

Explanation:

Step1: Identify mole ratio

From the balanced equation \( 3\text{Pb(NO}_3\text{)}_2 + 2\text{AlCl}_3
ightarrow 3\text{PbCl}_2 + 2\text{Al(NO}_3\text{)}_3 \), the mole ratio of \( \text{Pb(NO}_3\text{)}_2 \) to \( \text{Al(NO}_3\text{)}_3 \) is \( \frac{3}{2} \).

Step2: Set up proportion

Let \( x \) be moles of \( \text{Pb(NO}_3\text{)}_2 \). We have \( \frac{3}{2} = \frac{x}{12} \).

Step3: Solve for \( x \)

Cross - multiply: \( 2x = 3\times12 \). Then \( 2x = 36 \), so \( x=\frac{36}{2}=18 \).

Answer:

18