Answer:
a) Exothermic reaction.
b) Internal energy of system will increased.
Step-by-step explanation:
Given that
Work done on the gas = 526 J
Heat released from cylinder = 260 J
We know that when heat is released then it is called exothermic reaction and when heat is absorbed then it is called endothermic reaction .
So here heat is released so it is exothermic reaction.
From first law of thermodynamics
Q= ΔU +W
Heat is released so it will be taken as negative sign and also work is done on the system so it will be taken as negative sign.
Q= ΔU +W
- 260 = ΔU - 526
ΔU = 266 J
So we can say that internal energy of system will increased.