, , (U), (), (S) (- (G). :
= U + p × V,
G = - T× S,
p, V, - , . U, H, S , .. , , .
. , , , , dU .
dU = dQ - p×dV, (1)
dQ - , , , .
, , , , - . , , .
(V= const) : QV = DU; - Q = D. , (1). , , . .
, () :
DHo..= (Sni×DHiof) - (Snj×DHjof) ,
n - , .
() 1 , . =1,013×105 =298 . , . Df298 . Df298 - /.
1
2NaOH() + CO2() = Na2CO3() + H2O()
(/): NaOH()- -426,6, Na2CO3()- -1129, CO2()- -393,51, H2O()- -285,8.
DHo..= (Sni×DHiof) - (Sni×DHiof) =
|
|
=[1×Df298 (Na2CO3)+1× Df298(H2O)]- [2×Df298(NaOH)+1×Df298(CO2)]=
= -1129 - 285,8 + 2 × 426,6 + 393,51 = -168,1
2NaOH() + CO2() = Na2CO3() + H2O(); DHo = -168,1 .
: DHo. - , . . Df298 - /, n - .
2
Df298(2)= -393,5/
() + 2N2O() = CO2 () + 2N2(): DHo = -557,5
N2O().
DHo = [1×Df298(CO2) + 2×Df298(N2)] -[1×Df298() + 2×Df298(N2O)],
Df298(N2O)=1/2×[DHo + Df298()- Df298(CO2) - 2Df298(N2)]=
=82 /.
, , , , , .
3
, 100 25, , .
() | 2 () | ()2 () | |
Df298, / | -635,1 | -285,8 | -986,2 |
() + 2() = ()2() DHo =?
DHo = (Sni×DHiof). - (Sni×DHiof).. = 986,2 + 635,1 + 285,8 = -65,3 .
, (65,3 ) 1 . , :
n() = m(CaO)/M(CaO) = 100/(40+16) = 1,78 .
Q = 65,3 /( )× 1,78 ( ) = 116,61 .
4
, , 24 804,48 ..
+ 2 = 2, D =?
1 (12 ) . , 24 , 24/12 (/)=2 . , 1
D = 804,48 /2=402,24 / .
() + 2 ()= 2 (), D = -402,24 .