General Organic Chemistry Question 15
Question 15 - 31 January - Shift 2
In Dumas method for the estimation of $N_2$, the sample is heated with copper oxide and the gas evolved is passed over :
(1) $Ni$
(2) Copper gauze
(3) Pd
(4) Copper oxide
Show Answer
Answer: (2)
Solution:
Formula: Duma’s Method
Duma’s method.
The nitrogen containing organic compound, when heated with $CuO$ in a atmosphere of $CO_2$, yields free $N_2$ in addition to $CO_2$ and $H_2 O$.
$ \begin{aligned} & C_x H_y N_z+(2 x+\frac{y}{2}) CuO \to \\ & \quad x CO_2+\frac{y}{2} H_2 O+\frac{z}{2} N_2+(2 x+\frac{y}{2}) Cu \end{aligned} $
Traces of nitrogen oxides formed, if any, are reduced to nitrogen by passing the gaseous mixture over heated copper gauze.
