Question

If a system's internal energy increases by 250 kJ after the addition of375 kJ of energy as heat, what was the value ofthe work in the process?

(A) -625 kJ
(B) -125 kJ
(C) 125 kJ
(D) 625 kJ

Answer 1

(B) -125 kJ

Step-by-step explanation:

Going by the First Law of Thermodynamics it states that"

"A system can do work and increase it's internal energy provided we supply heat."

ΔU= q+w-----------1

where U= the internal heat

q= the quantity of heat added or removed from the system

w= the work done

Given

ΔU= 250kJ

q= 375kJ

from equation 1 make w subject of the formula we have

w= ΔU-q

w= 250-350

w= -125kJ