Question

The value of enthalpy change (h) for the reaction c2h5oh(l)+3o2(g)2co2(g)+3h2o(l)at 27 oc is -1366.5 kj mol-1. The value of internal energy change for the above reaction at this temperature will be:

Answer 1

Here is what I have...

The balanced equation I have for ethanol is: C2H5OH(l) + 3O2(g) -> 2CO2(g) + 3H2O(g)

And from that, the three equations I have are:

C + O2 -> CO2  ... deta H = -393.5

H2 + 0.5OH -> H2O  ... deta H = -241. 8

2C + 3H2 + 0.5O2 -> C2H5OH  ... deta H = -277.7

Then I got:

(277.7) - (2 x 393.5) - (3 x 241.8) = -1234.7 kJ/mol