Question

consider the chemical equilibrium of the reaction.
nh₄oh(aq) ⇌ nh₄⁺(aq) + oh⁻(aq)
what will happen to the chemical equilibrium if nh₄cl is added to this solution?
the chemical equilibrium will shift to the right.
the chemical equilibrium will not shift.
the chemical equilibrium will shift to the left.
the chemical equilibrium will be lost.

Explanation:

1. First, analyze the dissociation of \(NH_4Cl\): \(NH_4Cl(aq)

ightarrow NH_4^+(aq)+Cl^-(aq)\).

1. Then, consider the original equilibrium: \(NH_4OH(aq)

ightleftharpoons NH_4^+(aq)+OH^-(aq)\).

1. When \(NH_4Cl\) is added, the concentration of \(NH_4^+\) ions in the solution increases (because \(NH_4Cl\) dissociates to produce \(NH_4^+\)).
2. According to Le Chatelier's principle, if a stress (in this case, an increase in the concentration of a product, \(NH_4^+\)) is applied to a system at equilibrium, the system will shift in a direction that relieves the stress.
3. To reduce the increased concentration of \(NH_4^+\), the equilibrium will shift to the left (towards the reactants, \(NH_4OH\)), because the reverse reaction (combination of \(NH_4^+\) and \(OH^-\) to form \(NH_4OH\)) will be favored to consume the excess \(NH_4^+\) ions. Also, chemical equilibrium is a dynamic state and is not "lost" by adding a substance; it just shifts. So the equilibrium shifts to the left.

Answer:

The chemical equilibrium will shift to the left.