Question

Indicate whether you would expect the entropy of a system to increase or decrease of the

following: (i) N2

(g) + 3H2

(g) → 2NH3

(ii) O2

(g) → 2O(g)

Answer 1

it will increase definitely

Answer 2

Answer: i) decrease in entropy

ii) increase in entropy

Explanation: Entropy is the measure of degree of randomness or disorder.

In i) $N_2(g)+3H_2(g)\rightarrow 2NH_3(g)$

In this reaction 4 moles of gaseous reactants are converting to 2 moles of gaseous products. thus the randomness will decrease and hence entropy will also decrease.

ii) $O_2\rightarrow 2O$

In this reaction 1 gaseous molecule is getting converted to two gaseous  atoms thus the randomness will increase and hence entropy will also increase.