Question

Use the chemical equation to answer the question.

2HCl(ag) + Zn(s) → ZnCl2(aq) + H2(g)

The molar mass of hydrogen (H) is 1g/mol, the molar mass of chlorine (Cl) is 35g/mol, and the molar mass of zinc (Zn) is 65g/mol. When 130g of zinc react completely in hydrochloric acid (HCl), how much is the total mass of the products?

(1 point)
Responses

144g
144g

270g
270g

274g
274g

130g
130g

Answer 1

To determine the total mass of the products when 130 g of zinc reacts completely with hydrochloric acid (HCl), we first need to calculate the moles of zinc used in the reaction.

1. Calculate the moles of zinc (Zn):
\[
\text{Moles of Zn} = \frac{\text{mass of Zn}}{\text{molar mass of Zn}} = \frac{130 \, \text{g}}{65 \, \text{g/mol}} = 2 \, \text{mol}
\]

2. According to the balanced chemical equation:
\[
2 \, \text{HCl} + \text{Zn} \rightarrow \text{ZnCl}_2 + \text{H}_2
\]
From the equation, 1 mole of Zn produces 1 mole of ZnCl2 and 1 mole of H2. Therefore, 2 moles of Zn will produce 2 moles of ZnCl2 and 2 moles of H2.

3. Calculate the mass of each product:
- Mass of ZnCl2:
\[
\text{Molar mass of ZnCl}_2 = \text{Molar mass of Zn} + 2 \times \text{Molar mass of Cl} = 65 \, \text{g/mol} + 2 \times 35 \, \text{g/mol} = 65 + 70 = 135 \, \text{g/mol}
\]
\[
\text{Mass of ZnCl}_2 = \text{Moles of ZnCl}_2 \times \text{Molar mass of ZnCl}_2 = 2 \, \text{mol} \times 135 \, \text{g/mol} = 270 \, \text{g}
\]

- Mass of H2:
\[
\text{Molar mass of H}_2 = 2 \times \text{Molar mass of H} = 2 \times 1 \, \text{g/mol} = 2 \, \text{g/mol}
\]
\[
\text{Mass of H}_2 = \text{Moles of H}_2 \times \text{Molar mass of H}_2 = 2 \, \text{mol} \times 2 \, \text{g/mol} = 4 \, \text{g}
\]

4. Total mass of the products:
\[
\text{Total mass} = \text{Mass of ZnCl}_2 + \text{Mass of H}_2 = 270 \, \text{g} + 4 \, \text{g} = 274 \, \text{g}
\]

The total mass of the products when 130 g of zinc reacts completely in hydrochloric acid is **274 g**.