Question

Answer the following: 
(i) What is biuret test?
(ii) Write a balanced equation for the formation of biuret.

Answer 1

(i)

Biuret test: When urea is heated just above its melting point it forms a compound called biuret which gives a violet colour with dilute copper sulphate solution in alkaline medium.

(ii)

\[\ce{\underset{\text{Urea}}{2NH2CONH2} ->[Δ>132°C]\underset{\text{Biuret}}{NH2CONHCONH2} + NH3}\]