Chemical Thermodynamics Part 1

Entropy will decrease in A,B,C and D processes.
A, B→ Freezing of water will decrease entropy as particles will move closer and forces of attraction will increase. This leads to a decrease in randomness. So, entropy decreases.
(A) Water

0∘C

⟶

ice; ∆S=− ve
(B) Water

−10∘C

⟶

ice; ∆S=− ve
(C) N2(g)+3H2(g)⟶2NH3(g);∆S=− ve
Number of moles are decreasing
n=2−(3+1)
n=−2
So, entropy decreases.
(D) Adsorption; ∆S=− ve
Adsorption will lead to a decrease in the randomness of gaseous particles.
So, entropy decreases.
(E) NaCl(s)⟶Na+(aq)+Cl−(aq);∆S>0
The number of species on product side is more than the number of species on reactant side. So, entropy increases on dissolution of NaCl in water.