Question

In alkaline buffer solution containing NH₄OH and NH₄Cl , if some HCl is added its pH will

• A. increase a little
• B. decrease a little
• C. remains constant
• D. change but cannot be predicted

Answer 1

Answer: (B)

decrease a little

Answer 2

The addition of HCl causes the replacement of base (NH₄OH) with salt (NH₄Cl). The ratio of salt to base increases. Hence the pOH of buffer solution will increase and its pH will decrease.