Question

Methane undergoes combustion with O2 accordingto the following equation:CHA(g) + 2 02 (g) > CO2 (g) 2 H20 (1) AH = -213 kcal/mol CHAHow much heat (in kcal and kJ) is released duringthe combustion of 0.35 mol methane?

Answer 1

1) Chemical equation

$CH_4+2O_2\rightarrow CO_2+2H_2O\text{ }\Delta H=-213kcal_{}$

2) Heat released (kcal)

1 mol CH4 = -213 kcal

$Heat_{Rel}=0.35molCH_4\cdot\frac{-213kcal_{}}{1molCH_4}=-74.55kcal_{}$

0.35 mol CH4 releases -74.55 kcal.

3) Heat released (kJ)

74.55 kcal

1 kcal = 4.19 kJ

$Heat_{Rel}=-74.55\text{kcal}\cdot\frac{4.19\text{ kJ}}{1\text{kcal}}=-311.9\text{ kJ}$

0.35 mol CH4 releases -311.9 kJ