Choose the member with the higher entropy in each of the following pairs, and justify your choice [assume constant temperature, except in part (e)]
(a)1 mol of SO_2 (g) or 1 mol of SO_3 (g)
(b) 1 mol of CO_2 (s) or 1 mol of CO (g)
(c) 3 mol of O_2 (g) or 2 mol of O_3 (g)
(d) 1 mol of KBr(s) or 1 mol of KBr(aq)
(e) seawater at 2 ?C or at 23 ?C
Predict the sign of ?S_rxn^? and calculate its value for the combustion of 1 mol of propane at 25^0 C.
C_3 H_8 (g) + 5O_2 (g) ? 3CO_2 (g) + 4H_2 O(l)
Compound C_3 H_8 (g) O_2 (g) CO_2 (g) H_2 O(l)
S^? (J/K·mol) 269.9 205.0 213.7 69.9
At 298 K, the formation of ammonia has a negative ?S_sys^0; s
N_2 (g) + 3H_2 (g) ? 2NH_3 (g)
?S_sys(rxn)^0 = –197 J/K Calculate ?S_univ^0, and state whether the reaction occurs spontaneously at this temperature.
Question 3 Answer
At 298 K, the formation of ammonia has a negative