Question

State whether 0.1 M solutions of each of the following salts are acidic, basic, or neutral. Explain your reasoning for each by writing a balanced net ionic equation to describe the behavior of each nonneutral salt in water: NaCN, KNO3, NH4Cl, NaHCO3, and Na3PO4.

Answer 1

Answer:

1) NaCN is a basic salt

2) $KNO_3$ is a neutral salt

3) $NH_4Cl$ is an acidic salt

4) $NaHCO_3$ is a basic salt

5) $Na_3PO_4$ is a neutral salt

Explanation:

Salts are formed by the combination of an acid and a base. There are 3 types of salt:

• Acidic salt: It is formed by the combination of strong acid and weak base.
• Basic salt: It is formed by the combination of a strong base and weak acid.
• Neutral salt: It is formed by the combination of strong acid and strong base or weak acid and weak base.

For the given salts:

1) NaCN is a basic salt as it is formed by the combination of sodium hydroxide (strong base) and HCN (weak acid). The chemical equation for the hydrolysis of salt follows:

$NaCN+H_2O\rightarrow NaOH+HCN$

As NaOH is released in the solution. Thus, it is a basic salt.

2) $KNO_3$ is a neutral salt as it is formed by the combination of potassium hydroxide (strong base) and nitric acid (strong acid).

3) $NH_4Cl$ is an acidic salt as it is formed by the combination of ammonium hydroxide (weak base) and HCl (strong acid). The chemical equation for the hydrolysis of salt follows:

$NH_4Cl+H_2O\rightarrow NH_4OH+HCl$

As HCl is released in the solution. Thus, it is an acidic salt.

4) $NaHCO_3$ is a basic salt as it is formed by the combination of sodium hydroxide (strong base) and partial dissociation of carbonic acid (weak acid). The chemical equation for the hydrolysis of salt follows:

$NaHCO_3+H_2O\rightarrow NaOH+H_2CO_3$

As NaOH is released in the solution. Thus, it is a basic salt.

5) $Na_3PO_4$ is a neutral salt as it is formed by the combination of sodium hydroxide (strong base) and phosphoric acid (strong acid).