Question

Explain the separation techniques involved in the separations of constituents in gunpowder. What types of reactions are involved in the explosion of gunpowder?

Answer 1

Gunpowder is a mixture of sulphur, charcoal and potassium nitrate.

The chemical reaction of gunpowder:- $2{\mathrm{KNO}}_3\left(\mathrm{s}\right)+\mathrm{S}\left(\mathrm{s}\right)+3\mathrm{C}\left(\mathrm{powder}\right)\to {\mathrm{K}}_2\mathrm{S}\left(\mathrm{s}\right)+{\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{CO}}_2\left(\mathrm{g}\right).$

(i) Add water to the given mixture ${\mathrm{KNO}}_3$(Potassium nitrate) will dissolve in water, ${\mathrm{KNO}}_3\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{KOH}\left(\mathrm{s}\right)+{\mathrm{HNO}}_3\left(\mathrm{l}\right)$. Now, Filter the solution.

(ii) The filtrate will be the solution of ${\mathrm{KNO}}_3$ and residue that contains sulphur & charcoal.

(iii) Now, evaporate the filtrate & water will vaporize by leaving potassium nitrate (${\mathrm{KNO}}_3$) behind.

(iv) Add carbon disulphide$\left({\mathrm{CS}}_2\right)$ to the residue that contains sulphur & charcoal. By this sulphur will be dissolved.

(v) Now, filter this solution.

(vi) The filtrate will contain sulphur that is dissolved in $\left({\mathrm{CS}}_2\right)$and the residue will be of charcoal.

(vii) Now, to obtain the crystals of sulphur evaporate the filtrate.