Question

how many grams of alcl₃ are produced if 300 g of h₂ are produced?
2al + 6hcl → 2alcl₃ + 3h₂
the molar mass of alcl₃ is 133.33 g/mol.

1. 1320 g
2. 0.0743 g
3. 0.167 g
4. 2970 g
5. 5390 g
6. 655 g
7. 465 g

Explanation:

Step1: Calculate moles of $\text{H}_2$

Molar mass of $\text{H}_2$ is $2.016\ \text{g/mol}$.
$$n_{\text{H}_2} = \frac{30.0\ \text{g}}{2.016\ \text{g/mol}} \approx 14.88\ \text{mol}$$

Step2: Mole ratio of $\text{AlCl}_3$ to $\text{H}_2$

From reaction: $2\ \text{mol AlCl}_3 : 3\ \text{mol H}_2$
$$n_{\text{AlCl}_3} = n_{\text{H}_2} \times \frac{2}{3} = 14.88\ \text{mol} \times \frac{2}{3} \approx 9.92\ \text{mol}$$

Step3: Calculate mass of $\text{AlCl}_3$

Molar mass of $\text{AlCl}_3 = 133.33\ \text{g/mol}$
$$m_{\text{AlCl}_3} = 9.92\ \text{mol} \times 133.33\ \text{g/mol} \approx 1320\ \text{g}$$

Answer:

1. 1320 g