Answer to Question #122304 in General Chemistry for ASA

Question

if you were attempt to make 45 g of methane from CO2 and H2O (with O2 is also being produced), how much heat would be absorbed during the reaction?

Answer 1

CH₄ + 2O₂ → CO₂ + 2H₂O + energy (heat)

The combustion of of methane gas releases 802.3 kJ/mol CH₄.

M (CH₄) = 16.04 g/mol

So combustion of 1 mole (16.04 g) of methane gives us 802.3 kJ of heat. 45 g would produce:

45 / 16.04 = 2.805 mol

2.805 x 802.3 kJ = 2250.84 kJ or about 2.25 MJ of heat.

For the reverse reaction this amount of energy is absorbed.