Question about Chemistry

Question

What is the change in internal energy of a system if the surroundings absorb 145 J of heat

from the system while doing 98 J of work on the system?

Answer 1

∆U = q + w

∆U = change in internal energy

q = heat

w = work

∆U = -145 J + 98 J

∆U = -50 J

Note: we use a negative sign in front of q since heat was liberated FROM the system and we use a positive sign for w since work was done ON the system.