An organic compound having molecular mass 60 amu is found to contain 20% C, 6.67% Hand 46.67% N, while rest is oxygen. On heating it gives NH3 along with a solid residue. The solid residue gives violet colour with alkaline copper sulphate solution. The compound is

The ratio of atoms is

$\mathrm{C}:\mathrm{H}:\mathrm{N}:\mathrm{O}::\frac{20}{12}:\frac{6.67}{1}:\frac{46.67}{14}:\frac{26.26}{16}::1.67:6.67:3.19:1.64::1:4:2:1$

Hence, empirical formula is ${\mathrm{CH}}_4{\mathrm{N}}_2\mathrm{O}$

The reactions shown by the compound on heating is that of urea.

$\begin{array}{l}{\mathrm{H}}_2{\mathrm{NCONH}}_2⟶\mathrm{H}-\mathrm{N}=\mathrm{C}=\mathrm{O}+{\mathrm{NH}}_3\\ {\mathrm{H}}_2{\mathrm{NCONH}}_2+\mathrm{H}-\mathrm{N}=\mathrm{C}=\mathrm{O}\to {\mathrm{H}}_2{\mathrm{NCONHCONH}}_2\end{array}$

                                                                          biuret

  Biuret gives a violet colour with alkaline copper sulphate solution. Thus, the given compoundis  urea${\mathrm{H}}_2{\mathrm{NCONH}}_2$ .