Hello my name is helen (: this website is really cool ! if its not so much trouble i need help on a problem that i dont understand D:

a o.1964g sample of quinone (C6H4O2) is burned in a bomb calorimeter that has a heat capacity of 1.56 kj/°C. the temperature of the calorimeter increases by 3.2°C. Calculate the energy of combustion of quinone per gram and per mole.

thanks this would help me a lot

The heat capacity C is given by the formula
C = heat absorbed / increase in temp
or heat absorbed in a bomb calorimeter= C X increase in temp
=  1.56 kj/°CX  3.2°C.(please do calculations your self)
now this is the heat given out by combustion of o.1964g sample of quinone
Heat given by one g = 1.56 kJ/°CX  3.2°C. X 1g /o.1964g
Calculate number of moles of  quinine  in o.1964g sample
= mass / molar mass
heat liberated per mole = number of moles X 1.56 kj/°CX  3.2°C.

Quote from: Uma Sharma on December 08, 2009, 03:07:57 AM
The heat capacity C is given by the formula
C = heat absorbed / increase in temp
or heat absorbed in a bomb calorimeter= C X increase in temp
=  1.56 kj/°CX  3.2°C.(please do calculations your self)
now this is the heat given out by combustion of o.1964g sample of quinone
Heat given by one g = 1.56 kJ/°CX  3.2°C. X 1g /o.1964g
Calculate number of moles of  quinine  in o.1964g sample
= mass / molar mass
heat liberated per mole = number of moles X 1.56 kj/°CX  3.2°C.

thanks a lot it helped