1) Chemical equation
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O\text{ }\Delta H=-213kcal_{}[/tex]2) Heat released (kcal)
1 mol CH4 = -213 kcal
[tex]Heat_{Rel}=0.35molCH_4\cdot\frac{-213kcal_{}}{1molCH_4}=-74.55kcal_{}[/tex]0.35 mol CH4 releases -74.55 kcal.
3) Heat released (kJ)
74.55 kcal
1 kcal = 4.19 kJ
[tex]Heat_{Rel}=-74.55\text{kcal}\cdot\frac{4.19\text{ kJ}}{1\text{kcal}}=-311.9\text{ kJ}[/tex]0.35 mol CH4 releases -311.9 kJ