What does #K_(eq) # << 1 mean?

1 Answer
Jul 9, 2016

Answer:

That the equilibrium favours the reactant side.

Explanation:

For the reaction,

#A+BrightleftharpoonsC+D#

There is a rate forward, #K_f[A][B]#, and a rate backward, #K_r[C][D]#

When #"rate forward"="rate backward"#, this is by definition the very condition of chemical equilibrium, which is characterized by an equilibrium constant, #K_"eq"#.

#K_"eq"=([C][D])/([A][B])# #=# #K_"f"/K_"r"#

And thus, when #K_"eq"# is small, it means that at equilibrium the reverse rate is much greater than the forward rate, and that the equilibrium favours the reactant side.