In the free expansion of a gas, the heat transfer is zero but the work done and the change in internal energy may not be zero the work done, the heat transfer, and the change in internal energy all are zero the work done is zero but the heat transfer and change in internal energy may not be zero the change in internal energy is zero but the work done and the heat transfer may not be zero the work done, the heat transfer, and the change in internal energy all may not be zero

Change in internal energy, net heat transfer and work done are all zero in free expansion of gas.

Explanation:

In the free expansion of a gas,

the work done is zero

the heat transfer is zero

and the change in internal energy is zero

In free expansion,

Initial and final temperature are same, therefore T = T'

From the 1st law of thermodynamics

ΔU = Q - w   ,     where, ΔU is change in internal energy, Q is heat transfer and W is work done

We know that ΔU is a function of temperature only, therefore when initial and final temperature is same, then change in internal energy will be zero.

∴ΔU = 0

Therefore 1st law becomes

0 = Q - W

Q = W

Now in free expansion there is no heat transfer.

∴Q = 0

In Q = W ,   since Q = 0,

∴W = 0

Thus Change in internal energy, net heat transfer and work done are all zero in free expansion of gas.