Question

#20.14

Be sure to answer all parts. Styrene is produced by catalytic dehydrogenation of ethylbenzene at high temperature in the presence of superheated steam. (a) Given these data, find anº, AGⓇ and AS at 298 K: rxn rxn rxn Ahº AG f (kJ/mol) -12.5 (kJ/mol) 119.7 sº (J/mol K) 255 Ethylbenzene, CH-CH2CH3 Styrene, CH3-CH=CH2 103.8 202.5 238 Ahº Agº 45° rxn rxn rxn kJ kᎫ J/K (b) At what temperature is the reaction spontaneous? °C (c) What are AGⓇ and K at 600°C? rxn AG" K rxn kJ/mol * 104 Enter your answer in scientific notation.

Answer 1

Ans :- Reaction: De hydrogenation ç Hr - CH-CH₂ Ethyl Benzene » G H = CH=CH2 Styrene A HRrn AH Product AH Reactant → (Using the data given in the table) A Hethyl Benzene (-12.5 kJ mol (103.8 12.5 KJ BH Styrene 103.8 KJ mol mol Дн", Rnn 115.3 KJ mol Similarly A GRAN = AG styrene A Gersheyl Bengene - 119,7 XJ 202.5 KI mol mol AGR 82.8K I mol

Similarly - AS Roan - oso ASO styrene Ethyl Bengene 238 T 255 J mol Kelvin mol Kelvin - -1 J mol Kelvin

6) f A G = AH-TAS 82.8 RJ mel 7-17 116.3 KI T(-17 J mpl (82.8 -116.3) K mol Kel) 17T = Kel - 33.5X103 Kelvin 17 1970 Kelvin 1 19 Tlinac) =( 970-273) °c -2243°C -

A Groon at 600°C and Kat 600°c AGRn = A HRan TASRnn 116.3 KJ - (873 ke (873 / - 17 I mol mol Ket + 14. 8 84 mol = 131. 148 103 J (116 6.3 чку mol

for K at 600°C AG ° -RT In K 3 873 ket 131.14 X 10 8.314 Imolket X Ink - 0.0 18 8 103 In K +-0.0184103) K = - 1.5X108