Question

For which of the following processes would you expect there to be an increase in entropy? Ag+(aq) + Cl-(aq) AgCl(s) H2O(g) H2O(l) CaBr2(s) Ca+2(aq) + 2Br- (aq) CO2(g) CO2(s) N2(g) + 3F2(g) 2NF3(g)

Answer 1

Answer: $CaBr_2(s)\rightarrow Ca^{2+}(aq)+2Br^-(aq)$

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.

1. $Ag^+(aq)+Cl^-(aq)\rightarrow AgCl(s)$

The fast moving ions are converting to solid product, thus the entropy decreases.

2. $H_2O(g)\rightarrow H_2O(l)$

The fast moving gas is converting to liquid product, thus the entropy decreases.

3. $CaBr_2(s)\rightarrow Ca^{2+}(aq)+2Br^-(aq)$

The energy is absorbed by the reactants and the solid reactants are converting to fast moving ions, thus the entropy increases.

4. $CO_2(g)\rightarrow CO_2(s)$

The fast moving gas is converting to solid product, thus the entropy decreases.

5. $N_2(g)+3F_2(g)\rightarrow 2NF_3(g)$

4 moles of gas is converting to 2 moles of gaseous product , thus the entropy decreases.

Answer 2

CaBr₂(s) → Ca⁺²(aq) + 2Br⁻ (aq)     ΔS>0