Question

How many liters of oxygen are required to react completely with 1.2 liters of hydrogen to form water? 2H2(g) + O2(g) → 2H2(g)

Answer 1

Answer:

$\boxed{\text{0.60 L}}$

Explanation:

We can use Gay-Lussac's Law of Combining Volumes to solve this problem.

Gases at the same temperature and pressure react in the same ratios as their coefficients in the balanced equation.

1. Write the chemical equation.

Ratio: 2 L     1 L

           2H₂ + O₂ → 2H₂O

V/L:   1.2

2. Calculate the volume of O₂.

According to Gay-Lussac, 1 L of O₂ forms from 2 L of H₂.

Then, the conversion factor is (1 L O₂/2 L H₂).

$\text{Volume of O}_{2} = \text{1.20 L H}_{2}\times \dfrac{\text{1 L O}_{2}}{\text{2 L H}_{2}} = \textbf{0.60 L O}_{2}\\\\\text{You need }\boxed{\textbf{0.60 L of O}_{2}}$