Question

Can we use potassium in place of sodium for preparing Lassaigne's extract?

Answer 1

Lassaigne's extract:

1. Lassaigne's extract is a solution used in elemental analysis such as the presence of $\mathrm{N}$, $\mathrm{S}$, $\mathrm{X}$ (halides), etc.
2. It is prepared by heating the sample of salt strongly with sodium metal followed by plunging in water and then filtering the solution.
3. Potassium metal is more reactive than sodium it reacts violently on heating.
4. Hence, potassium cannot be used in place of sodium for preparing Lassaigne's extract.