For the following reaction, determine how many grams of [tex]\( \text{Zn}_3(\text{PO}_4)_2 \)[/tex] will be produced by 0.50 grams of [tex]\( (\text{NH}_4)_3\text{PO}_4 \)[/tex]:

[tex]\[
\begin{array}{c}
3 \, \text{ZnCl}_2 + 2(\text{NH}_4)_3\text{PO}_4 \rightarrow \text{Zn}_3(\text{PO}_4)_2 + 6 \, \text{NH}_4\text{Cl}
\end{array}
\][/tex]

A. 0.65 g
B. 1.20 g
C. 3.22 g
D. 7.24 g



Answer :

To determine how many grams of Zn₃(PO₄)₂ will be produced by 0.50 grams of (NH₄)₃PO₄, follow these steps:

1. Calculate the molar mass of (NH₄)₃PO₄:
- Molar mass of NH₄ (Ammonium ion): [tex]\( 14.01 (N) + 4.04 (H) = 18.05 \)[/tex] g/mol
- Since there are 3 NH₄ groups: [tex]\( 3 \times 18.05 = 54.15 \)[/tex] g/mol
- Molar mass of P (Phosphorus): [tex]\( 30.97 \)[/tex] g/mol
- Molar mass of O (Oxygen): [tex]\( 16 \)[/tex] g/mol, and there are 4 oxygens: [tex]\( 4 \times 16 = 64 \)[/tex] g/mol
- Total molar mass of (NH₄)₃PO₄: [tex]\( 54.15 + 30.97 + 64 = 149.12 \)[/tex] g/mol

2. Calculate the moles of (NH₄)₃PO₄:
- Given mass of (NH₄)₃PO₄: [tex]\( 0.50 \)[/tex] g
- Moles of (NH₄)₃PO₄: [tex]\( \frac{0.50 \text{ g}}{149.12 \text{ g/mol}} = 0.003353 \)[/tex] mol

3. Determine the moles of Zn₃(PO₄)₂ produced:
- From the balanced chemical equation:
[tex]\( 3 \text{ ZnCl}_2 + 2 \text{ (NH}_4\text{)}_3 \text{PO}_4 \rightarrow \text{ Zn}_3(\text{PO}_4)_2 + 6 \text{ NH}_4 \text{Cl} \)[/tex]
- 2 moles of (NH₄)₃PO₄ produce 1 mole of Zn₃(PO₄)₂.
- Therefore, moles of Zn₃(PO₄)₂ produced: [tex]\( 0.003353 \times \frac{1}{2} = 0.001677 \)[/tex] mol

4. Calculate the molar mass of Zn₃(PO₄)₂:
- Molar mass of Zn (Zinc): [tex]\( 65.38 \)[/tex] g/mol, and there are 3 Zn atoms: [tex]\( 3 \times 65.38 = 196.14 \)[/tex] g/mol
- Molar mass of P (Phosphorus): [tex]\( 30.97 \)[/tex] g/mol, and there are 2 P atoms: [tex]\( 2 \times 30.97 = 61.94 \)[/tex] g/mol
- Molar mass of O (Oxygen): [tex]\( 16 \)[/tex] g/mol, and there are 8 O atoms: [tex]\( 8 \times 16 = 128 \)[/tex] g/mol
- Total molar mass of Zn₃(PO₄)₂: [tex]\( 196.14 + 61.94 + 128 = 386.08 \)[/tex] g/mol

5. Calculate the mass of Zn₃(PO₄)₂ produced:
- Moles of Zn₃(PO₄)₂: [tex]\( 0.001677 \)[/tex] mol
- Mass of Zn₃(PO₄)₂: [tex]\( 0.001677 \text{ mol} \times 386.08 \text{ g/mol} = 0.647 \)[/tex] g

Therefore, 0.50 grams of (NH₄)₃PO₄ will produce approximately 0.647 grams of Zn₃(PO₄)₂. The correct answer from the given options is:
[tex]\[ 0.65 \text{ g} \][/tex]