Q. In which of the following processes, entropy increases?
(I) A liquid crystallizes into a solid
(II) Temperature of a crystalline solid is raised from to
(III)
(IV)

 3029  217 Thermodynamics Report Error

Solution:

(I) After freezing, the molecules attain an ordered state and therefore, entropy decreases
(II) At , the constituent particles are static and entropy is minimum. If temperature is raised to , these begin to move and oscillate about their equilibrium positions in the lattice and system becomes more disordered, therefore entropy increases
(III) In the reaction,

the number of gaseous components are increasing hence the entropy of system will increase
(IV)
In this decomposition, number of particles increase therefore, the randomness and entropy will also increase