Question

Select the correct answer.

Given:
2AI + 6HCI-2AlCl3 + 3H2
If the chemical reaction produces 129 grams of AlCl3, how many grams of H₂ are also produced?
OA 1.22
OB. 2.92
OC. 3.02
OD. 3.65

Answer 1

B.) 2.92

Step-by-step explanation:

Tp find the mass of H₂ produced, you need to (1) convert grams AlCl₃ to moles AlCl₃ (via molar mass), then (2) convert moles AlCl₃ to moles H₂ (via mole-to-mole ratio from equation coefficients), and then (3) convert moles H₂ to grams H₂ (via molar mass). It is important to arrange the ratios/conversions in a way that allows for the cancellation of units.

Molar Mass (AlCl₃): 26.982 g/mol + 3(35.453 g/mol)

Molar Mass (AlCl₃): 133.341 g/mol

2 Al + 6 HCl ---> 2 AlCl₃ + 3 H₂

Molar Mass (H₂): 2(1.008 g/mol)

Molar Mass (H₂): 2.016 g/mol

129 g AlCl₃ 1 mole 3 moles H₂ 2.016 g
------------------ x ------------------ x --------------------- x --------------- =
133.341 g 2 moles AlCl₃ 1 mole

= 2.93 g H₂

*our answers are most likely different due to using slightly different molar masses