0.5436g of liquid benzene c6h6 is burned with excess o2 in a constant pressure calorimeter

Question

0.5436g of liquid benzene c6h6 is burned with excess o2 in a constant pressure calorimeter, producing CO2 and H2O asthe only products. The temperature of the calorimeter, which has a heat capacity of 4.903 kj*K-1, rises from 25.021 C to 29.659 C

a.) Calculate the standard molar enthalpy for the combustion of benzene

b.) Calculate the standard molar enthalpy for the formation of benzene

Answer 1

1). Use q = C_calΔT where C_cal = 4.903 kJ/degree and ΔT = change in temperature. Solve for q which is the heat generated by the combustion.

2). To find molar enthalpy, convert 0.5436 g benzene to moles and the divide q by moles to get molar enthalpy of combustion.