Question

For reactions involving gases, the change in entropy (A.S ), is related to the change in the stoichiometric coefficients of the gaseous species in the reaction equation (Avgas). Determine the value of Avgas for each of the following equations and decide of the entropy increases, decreases, or has little or no change. a) K(s) + O2(8) KO, () ASA Avgas = O decreases increases has little or no change b) H (8) + Cl2(8) 2HCl() AS Avgus increases has little or no change decreases c) S(s) + O2(g) →SO (8) A Six Δντας = has little or no change increases decreases d) 2 NH,() N (8) + 3 H, () ASix Avgas = increases decreases has little or no change

Answer 1

∆Vgas =Volume of gaseous products - Volume of gaseous reactants

Volume of gases is directly proportional to the stochiometric number.

a) ∆V = 0-1= -1

∆S will decrease because amount of gaseous state decreases

b) ∆V = 2-2=0

∆S has little or no change

c) ∆V = 1-1=0

∆S has little or no change

d) ∆V = 4-2 = 2

∆S will increase as the amount of gaseous products is increased