Explain the term dynamic equilibrium?

1 Answer
May 13, 2018

Well, consider an equilibrium reaction.....#A+BrightleftharpoonsB+D#

Explanation:

There is a rate forward....

#"rate forward"=k_f[A][B]#...#k_f# is some unspecified constant..

And a rate backward...#"rate backward"=k_r[C][D]#

And equilibrium SPECIFIES EQUALITY of the forward and reverse rates, i.e.

#underbrace(k_f[A][B])_"rate backward"=underbrace(k_r[C][D])_"rate backward"#

And this #k_f/k_r=([C][D])/([A][B])#

And clearly, given the differential rates, forwards and backwards, the equilibrium is DYNAMIC.....

The quotient, #k_f/k_r# is otherwise known as #K_"eq"#, the thermodynamic equilibrium constant. It is a constant that must be measured.... And clearly, when #K_"eq"# is LARGE, the products are favoured at equilibrium. When #K_"eq"# is SMALL, the reactants are favoured at equilibrium.

Are you happy with this?