Question

Any buffer solution can be used as a buffer upto two pH units only.

• A. True
• B. False

Answer 1

The correct option is A True

Any buffer solution can be used as a buffer upto two pH units only. i.e. $p{K}_a\pm 1$. In other words the molar ratio of the salt and acid or base can be 10 or 1/10. If the ratio exceeds these limits, then it can not be used as a buffer. Best buffer is one in which the molar ration is 1, and $pH=p{K}_a$ or $pOH=p{K}_b$ because it can remain as a buffer for longer time.