"Heat cannot flow by itself from a body at a lower temperature to a body at a higher temperature". This statement corresponds to:

An ideal gas in a cylinder is separated by a piston in such a way that the entropy of one part is $S_{1}$ and that of the other part is $S_{2}$. Given that $S_{1} > S_{2}$. If the piston is removed,then the total entropy of the system will be:

State the main points of the second law of thermodynamics.

Entropy of a system decreases .........

Find the change in the entropy in the following process: $100 \, g$ of ice at $0^{\circ}C$ melts when dropped in a bucket of water at $50^{\circ}C$. (Assume the temperature of the water does not change). The result is in $cal/K$.

Water of mass $m$ gram is slowly heated to increase the temperature from $T_1$ to $T_2$. The change in entropy of the water,given specific heat of water is $1 \ J \ g^{-1} \ K^{-1}$,is