Question

Heat in the amount of 7.5 kJ is added to a closed system while its internal energy decreases by 12 kJ. How much energy is transferred as work? For a process causing the same change of state but for which the work is zero, how much heat is transferred?

Answer 1

W= 19.5 KJ

Q= -12 KJ

Step-by-step explanation:

Given that

Heat added to the system ,Q= 7.5 KJ

Change in the internal energy ,ΔU = - 12 KJ

Lets take work done in this process = W

We know that

Q= ΔU + W

Now by putting the values in the above equation

7.5 = -12 + W

W= 7.5 + 12 KJ

W= 19.5 KJ

If the work done is zero.

W= 0 KJ

Q= -12 KJ + 0 KJ

Q= -12 KJ

negative sign indicates that heat is rejected by the system.