1). .
2). , .
3). .
4). (Dn) ( ).
,
() + 2() = 2(), Dn = 1 Þ DS > 0.
(U) () . S298 [/(×)] . , S298 ( Df298) . , , , .
DS298 = (Sni ×Si298) - (Snj×Sj 298) .
, . = const, - ( ) DG
DG = D - ×DSo.
= const = const DG< 0. , - .
DG , , D DS
DG = (Sni×DGiof248) - (Snj×DGjof248)
5
,
SO2()+ NO2() SO3() + NO().
DGo . :
D. = (Sni×Dif298). - (Sni×Djf298)..
D. = Df298 (SO3) + Df298(NO) - Df298(SO2) - Df298(NO2) =
= -395,2 + 90,37 - (- 296,9 + 33,89) = - 41,82 () = 41,82 × 103 ()
DS = So(SO3) + So(NO) - So(SO2) - So(NO2) = 256,2 + 210,6 - (248,1 + 240,4) = -21,7().
DGo = D - DS = -41820 - 298 × (-21,7) = -35353 .
DGo = -35,4 < 0. Þ
298 .
DGo (DGof) , .
DG = (Sni×DGiof248) - (Snj×DGjof248j)
DG = -370,4 + 86,57 - (-300,4 + 51,84) = -35,27 .
DG = D - DSo .
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|
|
, () + 2() 2() . D DSo . .
DGo < 0:
DG = D - ×DSo < 0,
> D/DSo.
, D DSo ,
> D0298/DSo298.
D = 2 × Df298() - Df298(2) = 2 × (-110,5) - (-393,5) = 172,5 .
DS = 2S298() - [S298() + S298(2)] = 2 × 197,4 -(5,73 + 213,6) = 175,47 /.
> 172500/175,47 = 983 .
, 298 , ,
DG = D - DSo = 172500 - 198 × 175,47 = 120210 > 0.
DG , ( , 1 /, - 1 ) - . DG<0, , DG>0 - . () , DG=0. () () () -
DG = -R××ln K,
R - , 8,314 /(×); - , .
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(IV) 298 . . , .
NO2() | N2O4() | |
Df298 / | 33,89 | 9,67 |
S /(×) | 240,4 |
2NO2() N2O4()
D. = Df298(N2O4) - 2× Df298(N2) = 9,67 - 2 × 33,89 = -58,1
DS = S298(N2O4) - 2× S298(N2) = 304 - 2 × 240,4 = -176,8 /.
DG = -5,423 < 0.
Þ - . - :
DG = -R×T× ln K Þ ln = -DGo/(RT) = 5423/(8,314 × 298) = 2,18,
= 8,93
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, () + 2 () + 2() = 298 .
DG298 = DGof(2) - DGof() = - 228,6 - (-137,1) = -91,5 .
lg K = 91500/(8,314×2,302·298)16 Þ = 1016.
- . , ( ) .