Hint:The acidic buffer is formed by mixing a weak acid and salt of weak acid with a strong base. The basic buffer is formed by mixing a weak base and salts of weak base with a strong acid.
Complete step by step answer:
The buffer solution is defined as the solution containing water as a solvent. The mixture contains weak acids and its conjugate base or a weak base and its conjugate acid. The property of buffer solution is that when added in small amounts to the acidic solution or basic solution, it resists any change in the pH of the solution.
The pH of the buffer solution shows no change in addition to a small amount of acidic solution or basic solution. Therefore, the buffer solution is used to keep the pH of the solution constant.
The buffer solution is divided into acidic buffer and basic buffer.
The acidic buffer shows acidic pH and is formed by mixing a weak acid and salt of weak acid with a strong base. The pH of the acidic buffer is below 7.
The basic buffer shows basic pH and is formed by mixing a weak base and salts of weak base with a strong acid. The pH of the basic buffer is above 7.
NaCN is a salt of weak acid HCN and strong base NaOH. So it will form an acidic buffer.
Thus, the statement 0.5mmol of NaCN and 1mmol of HCl in 1 L solution is a buffer is false.
Therefore, the correct option is B.
The buffer solution in the fermentation process, in food preservatives, printing, transfer of blood oxygen which need specific hydrogen ion concentration. It is used in electroplating and drug delivery.