Answer to Question #121986 in Chemistry for Ikhenoba Joseph

Question

I have a problem with solving this question..

20cm3 of methane was released with 18cm3 of oxygen and it exploded.Calculate the volume of the resulting gas after the reaction mixture was cooled to room temperature.

Answer 1

The explosion and burning of methane with oxygen results in the formation of carbon dioxide and water according to the following reaction:

CH₄ + 2O₂ = CO₂ + 2H₂O

Next, the number of moles of methane and oxygen must by calculated. As 1 mol of gas occupies 22.4 L at standard conditions, the numbers of moles of methane and oxygen are:

n(CH₄) = V(CH₄) / 22.4 L = 20 cm³ / 22.4 L = 0.02 L / 22.4 L = 8.9 × 10^-4 mol

n(O₂) = V(O₂) / 22.4 L = 18 cm³ / 22.4 L = 0.018 L / 22.4 L = 8.04 × 10^-4 mol

As n(O₂) < n(CH₄), oxygen is a limiting reagent. As a result, it must be used to calculate the number of moles of carbon dioxide produced during the reaction. As 1 mole of CO₂ can be produced from two moles of oxygen:

n(CO₂) = n(O₂) / 2 = 8.04 × 10^-4 mol / 2 = 4.02 × 10^-4 mol

Finally, as 1 mol of gas occupies 22.4 L, carbon dioxide occupies:

V(CO₂) = n(CO₂) × 22.4 L = 4.02 × 10^-4 mol × 22.4 L = 9 × 10^-3 L = 9 cm³

Answer: 9 × 10^-3 L or 9 cm³