Given the following unbalanced thermochemical equation, how much heat will be released from the combustion of 45.5 grams of CH4 in an excess of oxygen gas?

CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) + 890 kJ

Heat released from the combustion of 45.5 grams of CH4 in excess oxygen gas is calculated as follows

calculate the number of CH4 moles used = mass/molar mass

= 45.5 grams / 15 g/mol = 2.84 moles

heat released is therefore = moles x 890 kj

= 2.84 x 890=2527.6 kj/mol