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How are dynamic equilibrium and reversible reactions connected to one another?

Answer 1

Caleb Adams

#"Dynamic equilibria are examples of reversible reactions....."#

For the generalized equilibrium reaction.....

#A+B rightleftharpoons C+D#

Now there is a #"rate forward"=k_f[A][B]#, where #k_f# is some unspecified rate constant...

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

Now by definition, equilibrium does NOT ENTAIL cessation of chemical change, but EQUALITY of FORWARD and REVERSE RATES. And so.....

#k_f[A][B]=k_r[C][D]#

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

And #k_f/k_r# is otherwise known as #K_"eq"#, the thermodynamic equilibrium constant, which must be measured for a particular reaction. And thus if #K_"eq"# is NUMERICALLY LARGE, the products are favoured at equilibrium, and if #K_"eq"# is NUMERICALLY SMALL, the reactants are favoured at equilibrium.

And thus equilibrium reactions are necessarily reversible. ARE you happy with this treatment?

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.