A solution contains the following:
NH3(aq) + H2O(l) <--> NH4+(aq) + OH-(aq)
Adding NH4Cl to this solution shifts the equilibrium of the given reaction to the left. What kind of reaction is this?
Do you have any answers from which to choose? I've never called it a type of reaction, other than an equilibrium equation and it shifts to the left because of Le Chatelier's Principle.
To determine the kind of reaction that occurs when NH4Cl is added to the solution, we need to understand the effect of NH4Cl on the equilibrium of the given reaction.
NH4Cl is a source of NH4+ and Cl- ions in the solution. When NH4Cl is added, it dissociates into NH4+ and Cl- ions. NH4+ can react with OH- from the dissociation of water according to the given reaction: NH3(aq) + H2O(l) <--> NH4+(aq) + OH-(aq).
When NH4Cl is added, the concentration of NH4+ increases in the solution. According to Le Chatelier's principle, increasing the concentration of a reactant shifts the equilibrium of a reaction to the opposite side. In this case, increasing the concentration of NH4+ would shift the equilibrium to the left (reactants side), decreasing the concentration of NH4+ and OH- and ultimately decreasing the concentration of NH3 and H2O in the solution.
Therefore, by adding NH4Cl to the solution, the equilibrium of the given reaction is shifted to the left. This indicates that it is a reaction that favors the formation of NH3 and H2O from NH4+ and OH-, and it is a reverse reaction to the forward reaction. So, the reaction is a reversible reaction.