Question

Δs is negative for the reaction __________.

a.2so2 (g) + o2 (g) → 2so3 (g)
b.nh4cl (s) → nh3 (g) + hcl (g)
c.pbcl2 (s) → pb2+ (aq) + 2cl- (aq)
d.2c (s) + o2 (g) → 2co2 (g)
e.h2o (l) → h2o (g)

Answer 1

The value of Δs (change in entropy) can be determined based on the stoichiometry of a reaction and the physical states of the reactants and products. In general, the entropy change is positive for reactions that produce more gas molecules than they consume, and negative for reactions that consume more gas molecules than they produce.

Step-by-step explanation:

The value of Δs (change in entropy) can be determined based on the stoichiometry of a reaction and the physical states of the reactants and products. In general, the entropy change is positive for reactions that produce more gas molecules than they consume, and negative for reactions that consume more gas molecules than they produce.

In the given reactions, the reaction with a negative change in entropy is option c. pbcl2 (s) → pb2+ (aq) + 2cl- (aq). This is because the number of gas molecules in the reaction remains the same, as the solid pbcl2 is converting into aqueous pb2+ and cl- ions.

Answer 2

ΔS =S(products) -S(reactants)

Where ΔS is the change of entropy in a reactions

a. ΔS = (2) - (2+1) = -1
b. ΔS = (1+1) -(1) = 1
c. ΔS = (1+2) - (1) = 2
d. ΔS = (2) - (2+1) = -1
e. ΔS = (1) - (1) = 0

ΔS is negative for reaction a. and d.