In: Chemistry
Concepts and reason
The concept used to solve this problem is that a buffer is formed by the combination of a weak acid and its salt of a strong acid or by the combination of a weak base and its salt of a strong acid.
Fundamentals
A buffer solution is a solution that resists change in \(\mathrm{pH}\) on the addition of a strong base or a strong acid. Buffer solutions are of 2 types:
1. Acidic buffer- This is formed by weak acid and its salt of a strong base.
2. Basic buffer- This is formed by a weak base and its salt of a strong acid.
To form a buffer solution you must mix a weak acid and a weak base on an aqueous solution.
The last option: HCN and NaCN will form a buffer.
Once you put HCN and NaCN in water will occur the following molecular dissociation:
HCN -----> H+ + CN-
NaCN -----> Na+ + CN-
The HCN will act as a weak acid and NaCN as a conjugated base.