14.00 g of Compound X with molecular formula C4H6 are burned in a constant-pressure calorimeter containing 20.00 kg of water at 25°C. The temperature of the water is observed to rise by 7.614°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.
Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.