Chimie fizică generală - Lorentz JÄNTSCHI
Chimie fizică generală - Lorentz JÄNTSCHI
Chimie fizică generală - Lorentz JÄNTSCHI
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o<br />
&<br />
+ & & & & bcx&<br />
2 2 2<br />
2 2<br />
bxx 2abx<br />
x − bx<br />
− abx x = −xb<br />
x −<br />
2 2 2 2<br />
3<br />
o bx&x<br />
& + abx x&<br />
− bx&<br />
+ x&<br />
b x + bcx&<br />
+ abcx = 0<br />
2 2 2<br />
3<br />
o x&x<br />
& + ax x&<br />
− x&<br />
+ x&<br />
bx + cx&<br />
+ acx = 0<br />
o<br />
x&<br />
&x<br />
& =<br />
2<br />
o v = x&<br />
;<br />
2<br />
2<br />
− ax x&<br />
− x&<br />
bx − cx&<br />
− acx<br />
x<br />
dv<br />
& x & = v ;<br />
dx<br />
dv<br />
v<br />
dx<br />
v<br />
=<br />
2<br />
3<br />
3<br />
− abcx<br />
2<br />
− ( a + b)<br />
x v − cv − acx<br />
x<br />
÷ abordare corectă (căutarea unei soluţii numerice):<br />
o model: R +R ↔ R* + R → P; [R] = x; [R*] = y; [P] = z;<br />
2 2<br />
o ecuaţii diferenţiale: x&<br />
= −ax<br />
+ bxy ; y&<br />
= ax − bxy − cy ; z & = cy<br />
o condiţii iniţiale: x(0)=R0; y(0)=0; z(0)=0;<br />
o iteraţii:<br />
2<br />
xi = i−1<br />
i−1<br />
i−1<br />
i−1<br />
x + ( −ax<br />
+ bx y ) Δt<br />
<br />
2<br />
yi = yi<br />
−1<br />
+ ( axi<br />
−1<br />
− bxi<br />
−1yi<br />
−1<br />
− cyi−1)<br />
Δt<br />
z + cy Δt<br />
zi = i−<br />
1 i−1<br />
o aplicaţie numerică:<br />
<br />
x<br />
y<br />
i<br />
i<br />
i<br />
y = y<br />
z = z<br />
0<br />
= x<br />
a = 10<br />
i−1<br />
i−1<br />
i−1<br />
0; z<br />
−2<br />
+ ( −ax<br />
+ ( ax<br />
+ cy<br />
0<br />
2<br />
i−1<br />
i−1<br />
0; x<br />
; b = 10<br />
2<br />
i−1<br />
Δt<br />
0<br />
−3<br />
÷ foaie de calcul Excel - figura 2.8.<br />
o<br />
=<br />
=<br />
+ bx<br />
− bx<br />
= R<br />
i−1<br />
0<br />
; c = 10<br />
i−1<br />
y<br />
−5<br />
y<br />
i−1<br />
i−1<br />
) Δt<br />
− cy<br />
i−1<br />
= 1; Δt<br />
= 10<br />
) Δt<br />
Figura 2.8. Iteraţia Mecanismului Lindemann - Hinshelwood<br />
-2<br />
=0 =B5 =B6 =B7<br />
=D2+1<br />
=E2+(-B$1*E2^2+B$2*E2*F2)*B$4 =F2+(B$1*E2^2-B$2*E2*F2-B$3*F2)*B$4<br />
3<br />
=G2+B$3*F2*B$4<br />
CFG-36