How do the rates of the forward and reverse reactions compare at a state of dynamic chemical equilibrium?
1 Answer
May 4, 2018
They are equal, and NONzero.
At dynamic chemical equilibrium, the rates of the forward and reverse reactions are equal to each other, i.e.
aA+bBk1 ⇌cC+dD
k−1
For this, assuming the equilibrium consists of elementary reactions, the forward rate law and reverse rate law are:
r1(t)=k1[A]a[B]b
r−1(t)=k−1[C]c[D]d
At equilibrium,
k1[A]a[B]b=k−1[C]c[D]d
From this, we obtain:
K≡k1k−1=[C]c[D]d[A]a[B]b
We know that rate constants are temperature-dependent, and thus, so is
It is also important to note that the rates of the forward and reverse reactions MUST be nonzero to have a dynamic chemical equilibrium.