Question

2agno₃ + cacl₂ → 2agcl + ca(no₃)₂
80.00 g agno₃ react with 30.00 g cacl₂ to form solid agcl. which is the limiting reactant?

1. agno₃ 2. cacl₂

enter the answer choice number.

Explanation:

Step1: Calculate moles of \(AgNO_3\)

Molar mass of \(AgNO_3\) is \(107.87 + 14.01 + 3\times16.00 = 169.88\space g/mol\).
Moles of \(AgNO_3=\frac{80.00\space g}{169.88\space g/mol}\approx0.471\space mol\).

Step2: Calculate moles of \(CaCl_2\)

Molar mass of \(CaCl_2\) is \(40.08 + 2\times35.45 = 110.98\space g/mol\).
Moles of \(CaCl_2=\frac{30.00\space g}{110.98\space g/mol}\approx0.270\space mol\).

Step3: Compare mole ratios

From reaction \(2AgNO_3 + CaCl_2
ightarrow2AgCl + Ca(NO_3)_2\), the ratio \(AgNO_3:CaCl_2\) is \(2:1\).
For \(0.270\space mol\) of \(CaCl_2\), required \(AgNO_3 = 2\times0.270 = 0.540\space mol\).
But we have only \(0.471\space mol\) of \(AgNO_3\) (less than \(0.540\space mol\)). So \(AgNO_3\) is limiting.

Answer:

1