The volume of a gas decreases from 500 cc to 300 cc when a sample of gas is compressed by an average pressure of 0.6 atm. During this process 10J of heat is liberated. The change in internal energy is

Here: Change in
Volume (V) = 500 - 300 = 200cc = 0.2 litre,,
Pressure (P) = 0.6atm and heat liberated (q) = 10J
Work done (W) = P$∆$V = (0.2x 0.6) = 0.12litre - atm
But 1 litre - atm = 101 .3 J .
hence W = 0.12x101.3 = 12.l56J .We also know that heat is liberated, therefore it would be negative. Thus change in $∆$E = q+W = -10 +12.16 = 2.16J.