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

Hint: 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