chem exam '08

[jasoN-]

i was just looking over the 2008 chemistry exam 2 (vcaa) and i got confused at this question:

Question 2
Two experiments are carried out. Both involve the combustion of 2.09 g of ethanol.
a. Experiment 1
Ethanol is used to calibrate a bomb calorimeter. 2.09 g of ethanol is placed in the bomb calorimeter and
reacted with excess oxygen. After the reaction is complete, the temperature of the water surrounding the
bomb in the calorimeter has increased by 33.2°C.
Calculate, to an appropriate number of significant figures, the calibration factor of the calorimeter, in
kJ°C–1.

solution:

n(CH3CH2OH) = 2.09 / 46.0*
= 0.0454 mol
Energy released = 0.0454 x 1364*
= 62.0 kJ
CF = 62.0/33.2
= 1.87 **

where did they get that value of the enthalpy? is this a standard reaction that we need to know? i'm confused

[Russ]

I didn't check, but I'm going to say it's in the data booklet because it's a common one (ie ethanol)

[jasoN-]

ah true that, alright thanks.
i felt pretty stupid when i couldn't find out what went wrong