Question

Given the values of Δ H ∘ rxn , Δ S ∘ rxn , and T below, determine Δ S univ(J/K) (for each part )

. A)ΔH∘rxn= 121 kJ , ΔS∘rxn=− 248 J/K , T= 297 K ,

B)ΔH∘rxn=− 121 kJ , ΔS∘rxn= 248 J/K , T= 297 K

C)ΔH∘rxn=− 121 kJ , ΔS∘rxn=− 248 J/K , T= 297K.

D)ΔH∘rxn=− 121 kJ , ΔS∘rxn=− 248 J/K , T= 546 K

Answer 1

Solution:

(A) ΔH^∘_rxn= 121 kJ, ΔS^∘_rxn= − 248 J/K and T= 297 K

Entropy change of surrounding

S_sr = 407.41 J/K

Therefore, entropy change of the universe

S_un = S_sr + ΔS_rx

S_un = 401.41 J/K + (− 248 J/K)

S_un = 159.41 J/K

(B) ΔH^∘_rxn= - 121 kJ, ΔS^∘_rxn= 248 J/K and T= 297 K

Entropy change of surrounding

S_sr = - 407.41 J/K

Therefore, entropy change of the universe

S_un = S_sr + ΔS_rx

S_un = - 401.41 J/K + ( 248 J/K)

S_un = - 159.41 J/K

(C) ΔH^∘_rxn= - 121 kJ, ΔS^∘_rxn= − 248 J/K and T = 297 K

Entropy change of surrounding

S_sr = - 407.41 J/K

Therefore, entropy change of the universe

S_un = S_sr + ΔS_rx

S_un = - 401.41 J/K + (− 248 J/K)

S_un = - 649.41 J/K

(D) ΔH^∘_rxn= - 121 kJ, ΔS^∘_rxn= − 248 J/K and T= 546 K

Entropy change of surrounding

S_sr = -221.612 J/K

Therefore, entropy change of the universe

S_un = S_sr + ΔS_rx

S_un = -221.612 J/K + (− 248 J/K)

S_un = -469.612 J/K