Question

Which of the following pairs constitutes a buffer?
(A) $HN{O_2}$ and $NaN{O_2}$
(B) $NaOH$and $NaCl$
(C) $HN{O_3}$ and $N{H_4}N{O_3}$
(D) $HCl$ and $KCl$

Answer 1

In order to find which pairs will constitute a buffer, we must first have an idea about what a buffer solution is? A buffer solution is a solution that consists of a mixture of weak acid along with its conjugate base or a mixture of weak bases along with its conjugate acid.

Complete step by step answer:
Let us first understand the buffer solution. A buffer solution is a solution that consists of a mixture of weak acid along with its conjugate base or a mixture of weak bases along with its conjugate acid. A buffer solution is a solution that is used to keep the pH of a solution constant.
There are two types of buffer solution, they are:
- Acidic buffer solution – pH of the acid buffer is below is 7.
- Basic buffer solution - pH of the acid buffer is above is 7.
Let us move onto the given question. $NaOH$ is a strong base, $HCl$ and $HN{O_3}$ are strong acids. Therefore, these cannot be used as a buffer solution. $HN{O_2}$ is a weak acid and $NaN{O_2}$ is a salt that is formed by the combination with a strong base $NaOH$. Therefore, $HN{O_2}$ and $NaN{O_2}$ are the buffer pairs present. So, the correct answer is “Option A”.

Note: Buffer solution is used for various purposes. They are:
- For food preservatives.
- Used in the fermentation process
- Drug delivery
- Electroplating
- Printing