Answer:
= 66.33 kCal
Explanation:
The combustion of methane is given by the equation;
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l); ΔH = -890.3 kJ/mol
The molar enthalpy of combustion of methane is -890.3 kJ/mol
This means 1 mole of CH4 yields 890.3 kJ/Mol
But, molar mass of methane is 16.04 g/mol
Therefore;
Heat produced by 5.0 g of methane will be;
= (5.0 g/ 16.04 g/mol)× 890.3 kJ/mol
= 277.525 kJ/mol
But; 1 kcal = 4.184 kJ
thus; = 277.525 /4.184
= 66.33 kCal