Question

46) All of the following have free energy of formation values of zero except a) Li (s) b) He (8) c) N (6) d) F2 (g) HF (B) If a process is both endothermic and spontaneous, then a) AU is less than 0 b) AH is less than 0 c) AG is greater than 0 d) AS is greater than 0 e) AH is equal to 0 48) The combination that always gives a spontaneous process is_ a) b) c) d) e) +AH AH AH -AH +/-AH +AS -AS *AS -AS +AS 49) Sublimation is an example of a process for which AH, AS, and AG are negative at all temperatures b) AH, AS, and AG are positive at all temperatures c) AH and AS are positive at all temperatures d) AH and AS are negative at all temperatures e) AH is negative and AS is positive at all temperatures 50) , If the entropy for a chemical change at 27°C is -10J/K and AH for the reaction is -20 AG is a) 2980 -3020 -17,000 -19,730 -23,000) b) c)

Answer 1

10 Option c is correct 1 In sublimation, we need cheat to transform solid to gas. Тоа би Уо For solid to sas, randomness increases, Henke osso OG=oH-TAS 15 16 Hence LG would be the only at high temperatures Option C is correct. (50) Os= OH , T=27% = 3ook HOTES on=-20 kJz-20000 AG - OH-TDS 2 -20o0o-300x L-10) = -20000 + 7000 = -17000J OG