Question

7) The equation depicted represents the essential change that takes place during the fermentation of glucose

(grape sugar) to ethanol (ethyl alcohol). Is Sº positive or negative? _______________ Explain

C₆H₁₂O₆(s) --> C₂H₅OH₆ (l) + 2CO₂(g)

b) Do you expect the entropy of the reaction represented to increase or decrease in the synthesis of urea,

H₂N-CO- NH₂, from ammonia, NH₃ and carbon dioxide, CO₂ ? ________________________ Explain.

2NH₃(g) + 2CO₂(g) --> H₂N-CO- NH₂(aq) + H₂O(l))

Answer 1

a)

C₆H₁₂O₆(s) --------------------------->   2 C₂H₅OH (l) + 2CO₂(g)

Sº positive because solid converts into pure liquid and gas. so randomness increases if randomness increases entropy also increases

b)

entropy decreases

2NH₃(g) + 2CO₂(g) --=---------------> H₂N-CO- NH₂(aq) + H₂O(l))

moles considerable form reactants = 2 + 2 = 4

moles considerable from products = 1

so reactant moles > products moles . in this case always entropy decreases