(Solved): 3.000g of Compound X with molecular formula C5H10 are burned in a constant-pressure calorim ...

$3.000\mathrm{g}$ of Compound $X$ with molecular formula ${\mathrm{C}}_5{\mathrm{H}}_{10}$ are burned in a constant-pressure calorimeter containing $50.00\mathrm{kg}$ of water at $25{}^{?}\mathrm{C}$. The temperature of the water is observed to rise by $0.6339^{?}\mathrm{C}$. (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 $25^{?}\mathrm{C}$. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.