Type the correct answer in the box. Express your answer to two significant figures.

An industrial vat contains 650 grams of solid lead(II) chloride formed from a reaction of 870 grams of lead(II) nitrate with excess hydrochloric acid. This is the equation of the reaction:

[tex]\[
2 HCl + Pb \left( NO_3 \right)_2 \rightarrow 2 HNO_3 + PbCl_2
\][/tex]

What is the percent yield of lead(II) chloride?

The percent yield of lead chloride is [tex]$\square$[/tex].



Answer :

To determine the percent yield of lead(II) chloride, we need to follow these steps:

1. Calculate the number of moles of lead(II) nitrate used in the reaction:
- Molar mass of lead(II) nitrate (Pb(NO₃)₂) = 331.2 g/mol.
- Mass of lead(II) nitrate used = 870 grams.

[tex]\[ \text{Moles of Pb(NO}_3\text{)₂} = \frac{\text{Mass of Pb(NO}_3\text{)₂}}{\text{Molar mass of Pb(NO}_3\text{)₂}} = \frac{870 \text{ g}}{331.2 \text{ g/mol}} = 2.63 \text{ moles} \][/tex]

2. Determine the theoretical yield of PbCl₂ (lead(II) chloride):
- From the balanced equation, 1 mole of Pb(NO₃)₂ produces 1 mole of PbCl₂.
- Molar mass of PbCl₂ = 278.1 g/mol.

[tex]\[ \text{Theoretical yield of PbCl₂} = \text{Moles of PbCl₂} \times \text{Molar mass of PbCl₂} = 2.63 \text{ moles} \times 278.1 \text{ g/mol} = 730.52 \text{ grams} \][/tex]

3. Calculate the percent yield:
- Actual yield of PbCl₂ = 650 grams.
- Theoretical yield of PbCl₂ = 730.52 grams.

[tex]\[ \text{Percent yield} = \left( \frac{\text{Actual yield}}{\text{Theoretical yield}} \right) \times 100\% = \left( \frac{650 \text{ g}}{730.52 \text{ g}} \right) \times 100\% = 89\% \][/tex]

The percent yield of lead chloride is [tex]\( 89\% \)[/tex].