PCl5 ⇄ PCl3 + Cl2
initial : a moli 0 0
reactioneaza: x
la echilibru : a - x x x
daca : sistemul ocupa volumul V=1 l ,
M = m totala /nr. moli = (m PCl5)/(a-x +x + x) = 72,55·2
[208,5 a ] / (a+x) = 145,1
208,5a = 145,1a + 145,1x
63,4a = 145,1x x = 0,43a
Kc = [PCl3]·[Cl2] /[PCl5] = 0,43²a / 0,57a = 0,324 mol/ l
%PCl5 transformat = x/a .100 = 0,43a/a .100 = 43%