Category Archives: Chemistry

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

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. Continue reading $N{H_2} – CO – N{H_2}\xrightarrow{NaOBr} {N_2}$

Nomenclature of Crown Ether

[18]-crown-6 has:

A) 18 Carbon & 6 Oxygen atoms
B) 6 Carbon & 18 Oxygen atoms
C) 12 Carbon & 6 Oxygen atoms
D) 6 Carbon & 12 Oxygen atoms

Key

Crown ether named [T]-crown-O, means T is the total number of atoms in the ring and O is the number of oxygen atoms in the ring.

For, [18]-crown-6 there are 6 Oxygen atoms and a total of 18 atoms.

So, number of Carbon atoms = 18 – 6 = 12

Hence, option (C).

The volume V of an enclosure contains a mixture ….

The volume V of an enclosure contains a mixture of three gases, 16 g of oxygen, 28 g of nitrogen and 44 g of carbon dioxide at absolute temperature T. Consider R as universal gas constant. The pressure of the mixture of gases is :

(A) $\frac {3RT}{V}$               (B) $\frac {5}{2} \frac {RT}{V}$
(C) $\frac {88RT}{V}$             (D) $\frac {4RT}{V}$ Continue reading The volume V of an enclosure contains a mixture ….

For the reaction $A(g) \rightleftharpoons B(g)$ at 495 K ….

For the reaction $A(g) \rightleftharpoons B(g)$ at 495 K, $\Delta_r G^\circ = -9.478 kJ.mol^{-1} $. If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B in the equilibrium mixture is _ _ _ _ millimoles. (Round off to the nearest integer)

[$R=8.314 J.mol^{-1} .K^{-1} $; ln 10 = 2.303 ] Continue reading For the reaction $A(g) \rightleftharpoons B(g)$ at 495 K ….