Chemical Reactions Heat +Work First Law

Question

A chemical reaction is run in which 380 Joules of heat are absorbed and 389 Joules of work are done on the system.

Calculate the change in the internal energy of the chemical system.

E =  Joules

Answer 1

Change in internal energy = ∆U = q + w where q = heat and w = work

q = +380 J (+ because heat is absorbed BY the system and is endothermic)

w = +389 J (+ because work is done ON the system)

∆U = 380 J + 389 J = 769 J