When 0.187 g of benzene, C6H6, is burned in a bomb calorimeter, the surrounding water bath rises in temperature by 7.48 ∘C. Assuming that the bath contains 250.0 g of water and that the calorimeter itself absorbs a negligible amount of heat, calculate combustion energies (ΔE) for benzene in both kilojoules per gram and kilojoules per mole.

Question

aaronq · Answer

q=m*c*dT

aaronq · Answer

C is specific heat capacity

anonymous · Answer

what does it have to do with dE?

anonymous · Answer

should the answer be 1.39?

aaronq · Answer

find the heat released by the the combustion of benzene using the equation, in this case q=E, because heat IS energy.

anonymous · Answer

could you answer this question...Liquid butane (C4H10), the fuel used in many disposable lighters, has ΔH∘f=−147.5 kJ/mol and a density of 0.579 g/mL. Use Hess’s law to calculate the enthalpy of combustion in kJ/mol.

aaronq · Answer

since q(benzene)=q(water), you need only to use the temperature difference, the mass of the water and the heat capacity of the water.

once you find q, you divide by the mass of benzene you used to find the units in J/g
then convert the mass to moles and divide q by the moles to get J/mol units.

aaronq · Answer

write a balanced equation first

anonymous · Answer

yes...what do i do next??

aaronq · Answer

you use Hess's law:

dH(rxn)=Hf(prod)-Hf(reactants)

anonymous · Answer

the Hf of h2o and co2 are not given

aaronq · Answer

you have to look them up in your book