Question

During adiabatic expansion of 2 moles of gas the internal energy is found to decrease by 2 joules. The work done is

Answer 1

We know,

There is no transfer of heat and matter take place during adiabatic expansion.

So,

dQ=0

According to first law,

dQ= dU + dW

0= -2J + dW ( As internal energy decreases by 2 J)

dW= -2J

Therefore, work done on the gas is -2 J and work done by the gas is 2 J.

Answer 2

the correct answer is 2joule.or -2joule. because W.D on the gas is -2 J.W.D by the gas is 2J