Question

Question 1: Explain the statements below :
A) Design a hypothetical change that provides the first law of thermodymability but is contrary to the second law.
b) Design a hypothetical change that provides the second law of thermodymability but is contrary to the first law.
c) Design a hypothetical state change that contrast the first and second laws of thermodymysis.

Answer 1

(A) Suppose an cold object is kept in contact to a hot object and the cold object looses heat which is gained by the hot object. As a result, the hot object gets even hotter while the cold object gets cooler.

In this process, first law is in as the amount of heat given to a body is equal to the sum of change in internal energy and work done (which is zero). Further, the amount of heat lost by one body is equal to the amount gained by the other body so energy is also conserved.

But this violates the second law as heat is transferred from colder body to hotter body spontaneously.

(B) Lets again take two bodies, one hotter and he other colder. Again they are kept in contact. So heat flows from hotter body to colder body. But the change in internal energy of the colder body is more than the hear given to it by the hotter body. That is, the final temperature is more than what we would expect.

So here second law is obeyed but first law is violated.

(C) An isolated system consists of 10 g of water at 10°C in contact with 10g of water at 0°C separated by a conducting wall. After some time is was found that the hotter water evaporated completely while the 0°C water froze to ice.

Here heat flows from colder water to hotter water which violates second law.

And the change in internal energy of the second water is more than the heat given by one. And also the work done is positve. So it violates first law too.