Benzoic acid dissociates in water to form hydrogen ions and benzoate ions. This reaction is an endothermic reaction:

C6H5COOH (aq) ⇌C6H5COO - (aq) + H + (aq)

Suppose this reaction is at equilibrium.

classify each changes as equilibrium shift toward reactants or equilibrium shifts toward products:

1. adding benzoate (C6H5COO-) ions

2. adding NaOH to remove hydrogen ions (H+)

3. adding benzoic acid (C6H5COOH)

4. increasing the hydrogen ion (H+) concentration.

5. cooling the solution.

Chemical equilibrium is the reaction state where the rate of reactants reacting is equal to rate of products deteriorating.

1. Adding benzoate ions to the mentioned equation will shift the equilibrium towards reactant side making more benzoic acid.

2. Adding NaOH to remove hydrogen ions will make the benzoic acid ionize more and hence shift the equilibrium towards products.

3. Adding benzoic acid more will shift the equilibrium towards products.

4. Increasing the hydrogen ion concentration will shift the equilibrium towards reactant, thereby crystalizing the benzoic acid.

5. Cooling the solution will also shift the equilibrium towards reactant side making effective crystals.