Chemical Forums
Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: electrogeek on May 04, 2019, 10:53:01 AM

Hi everyone,
I have been given the question that I've attached below about the use of the London formula to calculate the energy of interaction. I don't understand why the answer is positive however because I got a value of 8.74 kJ per mole...
Because all the numbers are positive which are going into the formula, the answer has to be negative like what I have calculated? Any help would be great because I've had another question on this formula and the same thing happens there where the answer is given to be positive but I calculate a negative value.
Cheers

Perhaps it is a matter of convention  are you asked about energy of interactions, or energy of formation?

Since the same symbol V is used in question and answer, it ought to refer to the same thing, and therefore be negative.

Thanks for the replies. I will have to ask my lecturer because on some revision problems which are about the same idea the values for V are negative in his mark scheme.
Thanks for checking though  just wanted to make sure there wasn't something that I was missing.