Answer to Question #94269 in Physical Chemistry for Abhishek

Question

Give the two statements of the second law of
thermodynamics given by (i) Clausius and
(ii) Kelvin. What is the entropy change of 3.5 mol
of an ideal gas during its isothermal and
reversible expansion from 2.5 x 10-3m3 to
0.25 m3?

Answer 1

(I)Heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time.

(II)It is impossible, by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects.

$\Delta S=nRln\frac{V_2}{V_1}=3.5·8.314·ln\frac{0.25}{2.5·10^{-3}}=134J$