Calculate the change internal energy (ΔE) for a system that is giving off 45.0 kJ of heat and is performing 855 J of work on the surroundings.

Question

anonymous · Answer

I thought it would be -44.1 but the answer key says -45.9

anonymous · Answer

try using mcat and the rest of the question

aaronq · Answer

giving off heat is negative and so is doing work.

$\Delta U=q+w=-45000~J+(-855~J)$

photon336 · Answer

If work is done on the system it's positive; if it's done to on the surroundings it's negative. if heat leaves the system q <0 if heat enters system q >0 total internal energy delta E = q+ w