14g of compound X with molecular formula C3H6 are burned in a constant-pressure calorimeter containing 10.00kg of water at 25°C. The temperature of the water is observed to rise by 15.58°C. (You may assume all the heat released by the reaction is absorbed by the water, and none by the calorimeter itself.) Calculate the standard heat of formation of compound X at 25°C.
a) -2430 kJ/mol
b) -485 kJ/mol
c) 485 kJ/mol
d) 2430 kJ/mol