Which of the following aqueous solutions will be basic in nature?

Concept:

Salt hydrolysis:

• When salts are treated with water, they give an acid and a base. This is called hydrolysis.
• Salts are generally strong electrolytes and thus are almost completely ionised in water.
• The acid and bases produced after hydrolysis can be classified as strong or weak depending on their nature.
• The pH of the resulting solution will depend on the strength of the acids and bases produced.
• This process is the reverse of neutralization reaction where an acid and a base are reacted to produce salt and water.

Explanation:

• Hydrolysis of sodium chloride yields sodium hydroxide and hydrochloric acid.
  • As both are strong, the resulting solution will be neutral.

​NaCl + H₂O→ NaOH (strong base) + HCl (strong acid)

• Hydrolysis of sodium acetate gives sodium hydroxide and acetic acid.
  • Acetic acid is a weak acid whereas sodium hydroxide is a strong base.
  • The strength of the base overpowers the strength of the acid and thus the resulting solution is basic in nature.

CH₃COONa + H₂O → ​CH3COOH (weak acid) + NaOH (strong base)

• Ammonium nitrate on hydrolysis produces ammonium hydroxide and nitric acid.

NH₄NO₃ + H2O → HNO₃  (strong acid) + NH₄OH (weak base)

• Ammonium hydroxide is a weak base whereas nitric acid is a strong acid.
• The acid overpowers the base and thus the resulting solution becomes acidic in nature.
• Potassium sulfate on hydrolysis yields potassium hydroxide and sulphuric acid.
  • As both are strong, the solution is neutral in nature.

Hence, the aqueous solution of sodium acetate will be basic in nature.