Do the units of the law of mass actions convey any meaning?

Since the number that you end up with, when calculating the value of the law of mass action for a given reaction often also has a unit, I was wondering if there is any physical meaning to this given unit or if it is basically "useless"?


Example:


$$\ce{CH3COOH <=> CH3COO- + H+}$$


$$K\_c = \frac{c(\ce{CH3COO-})\cdot c(\ce{H+})}{c(\ce{CH3COOH})}\qquad [K\_c] = \pu{mol L-1}$$




Well, you can calculate difference in number of moles of gases and active liquid species on reactant and product side species using units of $K\_c$ and $K\_p$, respectively, as these are mostly used for homogeneous reactions.


For example, the unit of $K\_c$ is $\text{(concentration)}^n$ if $n > 0$, more liquid or aqueous (ionic) species on product side.


Then, you can predict whether the product is formed or reactant when you increase or decrease external pressure or volume of a container containing a mixture in equilibrium. Temperature's effect would be only heat of reaction dependent.


Hint: write $K\_c$ in terms of moles and volume to check effect of volume, write $K\_p$ in terms of mole fractions and total pressure to check effect of external pressure.


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