Temperature-dependent pH of Aqueous Solutions of Salts

Explanation:

NaHCO3:
- The pH of the aqueous solution of NaHCO3 depends not only on temperature but also on the concentration of the salt.
- NaHCO3 is a weak base, and its pH will change with concentration due to the equilibrium between carbonic acid and bicarbonate ions.

CH3COONH4:
- The pH of the aqueous solution of CH3COONH4 is not solely dependent on temperature.
- CH3COONH4 is a salt of a weak acid (acetic acid) and a weak base (ammonia). The pH of its solution will be influenced by both the hydrolysis of the salt as well as temperature.

K2CO3:
- The pH of the aqueous solution of K2CO3 depends on both temperature and concentration.
- K2CO3 is a strong base, and its pH will change with concentration. Additionally, the solubility of K2CO3 increases with temperature, affecting the pH of the solution.

(NH4)2SO4:
- The pH of the aqueous solution of (NH4)2SO4 depends only on temperature.
- (NH4)2SO4 is the salt of a strong acid (sulfuric acid) and a weak base (ammonia). The pH of its solution will be influenced by temperature changes, as the dissociation of ammonium ions is not significantly affected by concentration.

In conclusion, among the given salts, only the pH of the aqueous solution of (NH4)2SO4 depends solely on temperature, while the pH of solutions of NaHCO3, CH3COONH4, and K2CO3 is influenced by both temperature and other factors such as concentration and the nature of the ions involved.