- #1

MarcL

- 170

- 2

## Homework Statement

Consider the combustion of octane that is burned in a bomb calorimter in the presence of 10.00kg of water. When burning 8.10mL of octane (.703g/ml=d) the temp. of the surrounding water increase by 5.66°C. The heat capacity of the bomb calorimter is 6.656Kj/ °C and the water is 4.184 j/g x °C

## Homework Equations

q=mcΔT

q

_{cal}=C

_{cal}x ΔT

ΔE

_{rxn}= q

_{rxn}/ moles of octane

## The Attempt at a Solution

find Q of water which gave me 236.8 KJ by q=mcΔT ( m = 10000KG )

and find Q cal which ended up to 37.13 KJ by q=C

_{cal}ΔT

then I added both Heat to get 273.9 Kj and then I divided by the number of mole found which was .049852045 moles.

However I got as an answer -5494.25 and the answer is -5506.3 Kj/mol

P.s: why does my textbook says to just use the Q of the calorimter and not add it up to the one of water in order to find the ΔE?