Question

1) What is ΔG^o (in kJ) at 35 ºC for the phase change of nitromethane from the liquid to the gaseous state?

CH₃NO₂(l) → CH₃NO₂(g)

CH₃NO₂(l): ΔH_f^o = -113.1 kJ/mol and S^o = 171.8 J/K mol)
CH₃NO₂(g): ΔH_f^o = -74.7 kJ/mol and S^o = 274.4 J/K mol)

2) At 298 K, ΔG^o = - 6.36 kJ for the reaction:

2N₂O(g) + 3O₂(g) ↔ 2N₂O₄(g)

Calculate ΔG (in kJ) at 298 K when P_N2O = 3.02 atm, P_O2 = 0.0060 atm, and P_N2O4= 0.724 atm.

Answer 1

CH3NO2 () -CHNO2 (9) T= 35°C = 308 K) AHn AHO products AHgeactants - tht- (-113.1) 38.4 KTIMol A Sproduct -ASYeactant 274.4-17I 8 102.6 JIK-mol AHITAS (38.yx to3)-3og x lo2.6 38400-31600.8 11 4.9 9.T mol 6.7992 KJ| mo 1 2 Nz04(9) 2 N209) t302 (7) P20= 3002 atm O.724 atm Po-O.0060 atm (०-३२५) :Keg (29 8)000.0) Kea 2.66078 X1D5 tn) 11 :AG -RT In CKea)

R= 8.314 Jmol-K 1 atm to1325 N/m2 T 298K Kea 2.66078 X1os (1.01325 xlo5)3 2. 557728x 10-10 8314 x 298 tn (2.5577 28 X lo-1 2477.572 X (-22.08673 1357) 14 54721.4671 J 11 54.7214677 X103 J 11 5५.१2।५ RJ