Heat energy Q is transferred spontaneously from a metal block at temperature Th to an identical block at temperature Tc(Th>Tc) in an otherwise isolated enclosure. Both blocks have the same constant heat capacity C over the small temperature changes involved.
(i) State the Clausius statement of the Second Law of Thermodynamics.
(ii) Write the mathematical expressions for the entropy change of each block when the heat Q flows directly from the hotter block to the colder block across the finite temperature difference.
(iii) Using the results of part (ii), explain why the total entropy change of the isolated system is positive and hence why the process is irreversible.