QUESTIOn! Please answer quickly! on law of thermodynamics!?

Question

for the following process, how do you calculate the change in internal energy of the system and determine whether the process is endothermic or exothermic

1. a 50g sample of water is cooled from 30 degrees celcius to 15 degrees celcius, thereby losing approsimatley 3140J of heat

Answer 1

The change in internal energy of a system is given by

DeltaE = q + w

Where q is heat supplied to the system and w is work done on the system.

In this case, the system is exporting heat, so q = - 3140J.it is not noticeably changing volume, so w = 0. And there you have it.

Since the system is exporting heat, that is what is meant by saying that the process is exothermic.

So actually the question is very easy, but is asked in such a contorted way as to make it look difficult.

Answer 2

DELTA(U) = replace in inner capability Q = warmth extra (+ if warmth pumped into equipment) W = Mechanical paintings W' = the different capability extra to equipment DELTA(U) = Q + W +W' in words, your problem could be written like, the replace of inner capability = the warmth extra to the equipment considering the fact which you haven't any longer have been given any paintings or the different capability source. Your answer is, U = -8.sixty 5 kJ and it fairly is an exothermic technique because of fact your equipment releases warmth into the ambience.