Question

Equal moles of sulfur dioxide gas and oxygen gas are mixed in a flexible reaction vessel and then sparked to initiate the formation of gaseous sulfur trioxide. Assume- ing that the reaction goes to completion, what is the ra- tio of the final volume of the gas mixture to the initial volume of the gas mixture if both volumes are measured at the same temperature and pressure?

Answer 1

Ratio of the final volume of the gas mixture to the initial volume of the gas mixture is 2 : 3

Step-by-step explanation:

Before proceeding, we have to write out the balanced chemical equation and this is given as;

sulfur dioxide gas + oxygen gas → gaseous sulfur trioxide

SO₂ + O₂ → SO₃

Upon balancing the equation, we have;

2SO₂ + O₂ → 2SO₃

From the equation, we can tell that 2 moles of SO₂ react with 1 moles of O₂ to give 2 moles of SO₃.

Applying gay lusaac's law;

Gay Lussac's Law of Combining Volumes states that when gases react, they do so in volumes which bear a simple ratio to one another, and to the volume of the product(s) formed if gaseous, provided the temperature and pressure remain constant.

This means 2 vol of SO₂ react with 1 vol of O₂ to give 2 vol of SO₃.

Initial volume of gas mixture (No product has been formed) = 2 vol of SO₂ + 1 vol of O₂ = 3 vol

Final volume of gas mixture (Reactants has been exhausted and product formed) = 2 vol of SO₃

Ratio (Final : Initial);

2 : 3