# What would happen to a weak base dissociation equilibrium if more products were added?

Feb 19, 2017

Just like any equilibrium reaction, when more products are added, Le Chatelier's principle tells us that the position of equilibrium shifts in the direction of the reverse reaction.

#### Explanation:

I will write the following generic dissociation of a weak base B, to help me explain:

${H}_{2} O + B r i g h t \le f t h a r p \infty n s H B + O {H}^{-}$

Adding more of the product $H B$ to this equilibrium will cause a shift to the left, resulting in a new equiibrium having a higher concentration of both ${H}_{2} O$ and $B$, a higher concentration of $H B$ (because the shift the Le Chatelier refers to is generally one which partially consumes the added material) and a lower concentration of $O {H}^{-}$.

Since the $\left[O {H}^{-}\right]$ has been reduced, the solution is now less basic that it was before $H B$ was added. The pH has decreased.