Question

2agno₃ + cacl₂ → 2agcl + ca(no₃)₂
what mass of cacl₂ is used up when 80.00 g agno₃ react?
? g cacl₂

Explanation:

Step1: Calculate moles of \( \text{AgNO}_3 \)

Molar mass of \( \text{AgNO}_3 \) is \( 107.87 + 14.01 + 3\times16.00 = 169.88 \, \text{g/mol} \).
Moles of \( \text{AgNO}_3 = \frac{80.00 \, \text{g}}{169.88 \, \text{g/mol}} \approx 0.4709 \, \text{mol} \).

Step2: Relate moles of \( \text{AgNO}_3 \) to \( \text{CaCl}_2 \)

From the reaction: \( 2 \, \text{mol AgNO}_3 \) reacts with \( 1 \, \text{mol CaCl}_2 \).
Moles of \( \text{CaCl}_2 = \frac{0.4709 \, \text{mol AgNO}_3}{2} \approx 0.23545 \, \text{mol} \).

Step3: Calculate mass of \( \text{CaCl}_2 \)

Molar mass of \( \text{CaCl}_2 = 40.08 + 2\times35.45 = 110.98 \, \text{g/mol} \).
Mass of \( \text{CaCl}_2 = 0.23545 \, \text{mol} \times 110.98 \, \text{g/mol} \approx 26.14 \, \text{g} \).

Answer:

\( 26.14 \)