Question

If work done by the system is 300 joule when 100 cal.heat is supplied to it. The change in internal energy during the process

Answer 1

As the work is done by the system and heat is supplied to the system.

Therefore,

q = 100 cal = 420J

w = −300 J

Now from first law of thermodynamics,

△U = q + W

∴ △U = 420 + (-300)

⇒ △U = 120 J