Question

Elemental boron can be formed by reaction of boron trichloride with hydrogen. BC13(g) + 1.5H2(g) → B(s) + 3HCl(g) Calculate AGº for the reaction at 500K. Substance BC13(g) H2(g) B(s) HCl(g) AH°F (kJ/mol): -403.8 -92.307 AG°f (kJ/mol): -388.7 o 0 -95.299 S°(J/K·mol): 290.1 130.7 5.86 186.9 AG° = -RTINK AG = RTinQ + AG° AG° = AH° - TAS° -78.6 kJ 293.4 kJ 78.6 kJ 86.7 kJ -86.7 kJ

Answer 1

We calculate the Enthalpy change of reaction and then entropy change of the reaction after that use the relation

Delta G = Delta H - T Delta H

T is 500 kelvin

We get delta G = 86.7 kJ/mol

Baz (G) + We smo os riesg) + " 8 001-f rechp) 049 3 2 1 1 2 19 ) ▼ - B (s) + 340 (g) Calculate the standard enthalpy change of Reaction OH = (Sum of standard enthelpy of Products -Sum of standard enthelp of Reactants , +3H BOS) IMG] 83 82 [3* (-92307) +0] - [ - 40318] 126 879 KI MORT sho = 126.879 kJ/mol -0 [ 3. + 3.57.00] HUI) B (5) B4C) (3 * 18619 + 185186] - [ 290.1 + 3x130.7) [ 566.56 – 466.157 = 80.41 JK /mol 80.41 JR / mol We know AGO OH- + Temperature T = 500k Agº (126.679 kJ/mol ) - 500*(80)41)3 K/mal AG 126899 J/mol 500XBO:41 J/mol 86674 J/mol oso 3.80 f ميه (3 090 1 KJ = 1037 86.674 KJ/mol option (IV) is correct. CS Scanned with CamScanner

Option (IV) is correct.