The pH of 0.1 M aqueous solution of NaCl, and will follow the order:

• a.) NaCl < CH₃COONa < NH₄Cl
• b.) NH₄Cl < NaCl < CH₃COONa
• c.) NH₄Cl < CH₃COONa < NaCl
• d.) NaCl < NH₄Cl < CH₃COONa

The pH of a 0.1 M aqueous solution of NaCl is typically around 7. This is because NaCl is a neutral salt formed from a strong acid (HCl) and a strong base (NaOH), which do not affect the acidity or basicity of the solution.

Comparing Different Salts

When considering the pH of other salts, such as NH₄Cl, the situation changes:

• NH₄Cl: This salt is formed from a weak base (NH₃) and a strong acid (HCl). Its solution tends to be acidic, with a pH lower than 7.
• NaCl: As mentioned, remains neutral with a pH around 7.

Summary of pH Values

In summary, the order of pH for the given salts in a 0.1 M solution would be:

1. NaCl - pH ≈ 7 (neutral)
2. NH₄Cl - pH < 7 (acidic)

Thus, the pH values reflect the nature of the salts and their components in solution.