Question

Assume that 5.94 x 10^3 kJ of energy is needed to heat a home. If this energy is derived from the combustion of methane (CH₄), how many moles of methane are burned? (ΔH° of combustion for CH₄ = -891 kJ/mol)

A) 6.66 moles
B) 5.94 moles
C) 10.56 moles
D) 3.34 moles

Answer 1

To find the number of moles of methane burned to produce 5.94 x 10^3 kJ of energy, divide the total energy by the energy released per mole of methane. The calculation yields 6.66 moles, making option A the correct answer.

Step-by-step explanation:

The question asks how many moles of methane are burned to produce 5.94 x 103 kJ of energy, given that the combustion of methane (CH4) has a ΔH° of combustion equal to -891 kJ/mol. To solve this, we use stoichiometric calculations and enthalpy changes:

1. First, we determine the amount of heat energy released by the combustion of 1 mole of methane, which is 891 kJ.
2. Then, we divide the total energy needed to heat the home (5.94 x 103 kJ) by the energy released per mole of methane (-891 kJ/mol) to find the number of moles of methane required.
3. Performing the calculation, 5.94 x 103 kJ / 891 kJ/mol = 6.66 moles.

The correct answer is A) 6.66 moles.