Question

If 2 kJ of heat is released from system and 6 kJ of work is done on the system, what is enthalpy change of system?

Options

• - 2 kJ

• + 8 kJ

• - 8 kJ

• + 6 kJ

Answer 1

- 2 kJ

Explanation:

Q = -2 kJ,    W = +6 kJ

∴ Δ U = Q + W

= - 2 + 6 = 4 kJ

Now, Δ H = Δ U - W 

= 4 - 6 = - 2 kJ