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Physics Guru is an online education and competitive examinations preparation portal founded by Manish Verma, an IIT Madras alumnus, providing learning resources for competitive examinations.

The emphasis is on conceptual understanding, analytical thinking and problem solving rather than simply memorising formulas and standard methods.

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$N{H_2} - CO - N{H_2}\xrightarrow{NaOBr} {N_2}$

Hydrazine formed from Urea is further oxidised to $N_2$ as shown below:

$N{H_2} - \mathop {\mathop C\limits^\parallel  }\limits^O  - N{H_2} \xrightarrow[\text{Hoffmann Bromamide Degradation}]{\text{NaOBr}} N{H_2} - N{H_2} \longrightarrow {N_2}$

Assuming 1 dL of blood sample contains 30 mg of Urea, calculate the volume of $N_2$ gas obtained at NTP from the sample.

Solution

From the reaction, 1 mol of Urea liberates 22.4 L $N_2$ at NTP

Or, 60 gm Urea liberates 22.4 L $N_2$ at NTP

Or, 1 gm Urea liberates $\frac {22.4}{60}$ L $N_2$ at NTP

Or, 30 mg Urea liberates $\frac{{22.4}}{{60}} \times 30 \times {10^{ - 3}}$ L $N_2$ at NTP

= $1.12 \times 10^{-2}$ L $N_2$ at NTP