The burning of propane gas can be represented as a balanced chemical reaction as follows: C3H8 (g) + 5O2 (g) →3CO2 (g) + 4H2O (g) Calculate the number of liters of water vapor produced when 25.0 liters of oxygen gas are consumed.

Answer: 20L of H2O

Explanation:

C3H8 + 5O2 → 3CO2 + 4H2O

Recall 1mole of a gas contains 22.4L at stp

5moles of O2 contains = 5 x 22.4 = 112L

4moles of H2O contains = 4 x 22.4 = 89.6L

From the equation,

112L of O2 produced 89.6L H2O

There for 25L of O2 will produce XL of H2O i. e

XL of H2O = (25 x 89.6) / 112 = 20L