When 0.515 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.243◦C is observed. What is Urxn for the combustion of compound X? The hardware component of the calorimeter has a heat capacity of 3.12kJ/◦C. The specific heat of water is 4.184J/g ·◦C, and the MW of X is 56.0 g/mol.

Question

When 0.515 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.243◦C is observed. What is Urxn for the combustion of compound X? The hardware component of the calorimeter has a heat capacity of 3.12kJ/◦C. The specific heat of water is 4.184J/g ·◦C, and the MW of X is 56.0 g/mol.
Answer in units of kJ/mol

DrBob222 · Answer

q = [mass H2O x specific heat H2O x (Tfinal-Tinitial)] + [Ccal x (Tfinal-Tinitial)] Then delta E/g = q/0.515 g delta E/mol = delta E/g x (56.0 g/mol)