Question

1.     For each of the following reactions indicate whether you would expect the entropy of the system to increase or decrease.

a)     CH₃OH_(l) ® CH₃OH_(g)

b)    N₂O_4(g) ®2NO_2(g)

c) 2KClO_3(s) ® 2KCl_(s) + 3O_2(g)

d) CH₃COOH_(l) ® CH₃COOH_(s)

Answer 1

1)

a)     CH₃OH_(l) -------------> CH₃OH_(g)

Entropy increases .

liquid to gases , the randomness of molecules increases. so entropy also increases.

b)    N₂O_4(g) -------------> 2NO_2(g)

Entropy increases .

here number of moles of products are more than reactants. so entropy increases.

c) 2KClO_3(s) ----------> 2KCl_(s) + 3O_2(g)

Entropy increases .

solid to gas Entopy increases.

d) CH₃COOH_(l) -----------> CH₃COOH_(s)

Entropy decreases.

liquid to solid . molecule randomness decreases. so entropy decreases