An organic compound having molecular mass `60` is fond to contain `C=20%`, `H=6.67%` and `N=46.67%` while rest is oxygen. On heating it gives `NH_(3)` alongwith a solid residue. The solid residue gives violet colour with alkaline copper sulphate solution. the compound is

Options

A. `CH_(3)NCO`
B. `CH_(3)CONH_(2)`
C. `(NH_(2))_(2)CO`
D. `CH_(3)CH_(2)CONH_(2)`

Answer

C

Explanation

`{:("Element","Percentage","Mole","Mole ratio"),(C,20,20//12=1.66,1),(H,6.67,6.67//1=6.67,4),(N,46.67,(46.67)/(14)=3.33,2),(O,26.66,26.6//16=1.66,1):}`
Empirical formula `=CH_(4)N_(2)O`
Out of these urea on heating gives a solid residue called biuret which gives violet colour with alkaline `CuSO_(4)` solution.
`underset("Urea")(NH_(2)CONH_(2)+H)NHCONH_(2) to underset("Biuret")(NH_(2)CONHCONH_(2))+NH_(3)`