On heating lead nitrate forms oxides of nitrogen and lead. The oxides formed are-
$1. {\mathrm{N}}_2\mathrm{O}, \mathrm{PbO}$
$2. {\mathrm{NO}}_2, \mathrm{PbO}$
$3. \mathrm{NO}, \mathrm{PbO}$
$4. \mathrm{NO}, {\mathrm{PbO}}_2$

Which of the following elements does not show allotropy?

1. Nitrogen

2. Bismuth

3. Antimony

4. Arsenic

The maximum covalency of nitrogen is-

1. 3

2. 5

3.  4

4.  6

Which of the following statements is wrong?

1. Single N—N bond is stronger than a single P—P bond.

2. ${\mathrm{PH}}_3$ can act as a ligand in the formation of coordination compound with transition elements.

3. ${\mathrm{NO}}_2$ is paramagnetic in nature.

4. Covalency of nitrogen in ${\mathrm{N}}_2{\mathrm{O}}_5$ is four.

A brown ring is formed in the ring test for ${\mathrm{NO}}_3^{-}$ ion. It is due to the formation of-

1. [Fe(H₂O)₅(NO)]²⁺
2. FeSO₄.NO₂ 
3. [Fe(H₂O)₄ (NO)₂]²⁺
4. FeSO₄. HNO₃

Elements of group-15 form compounds in +5 oxidation state. However, bismuth forms only one well-characterized compound in +5 oxidation state. The compound is-

$1. {\mathrm{Bi}}_2{\mathrm{O}}_5$
$2. {\mathrm{BiF}}_5$
$3. {\mathrm{BiCl}}_5$
$4. {\mathrm{Bi}}_2{\mathrm{S}}_5$

On heating ammonium dichromate and barium azide separately we get

1.  ${\mathrm{N}}_2$ in both cases

2.  ${\mathrm{N}}_2$ with ammonium dichromate and $\mathrm{NO}$ with barium azide

3.  ${\mathrm{N}}_2\mathrm{O}$ with ammonium dichromate and ${\mathrm{N}}_2$ with barium azide

4.  ${\mathrm{N}}_2\mathrm{O}$ with ammonium dichromate and ${\mathrm{NO}}_2$ with barium azide

In the preparation of ${\mathrm{HNO}}_3$, we get $\mathrm{NO}$ gas by catalytic oxidation of ammonia. The moles of NO produced by the oxidation of two moles of ${\mathrm{NH}}_3$ will be ......... .

1.  2

2.  3

3.  4

4.  6

In solid-state, PCl₅ exists as: 

Which of the following is correct for P₄ molecule of white phosphorus?

a. It has 6 lone pairs of electrons

b. It has six P — P single bonds

c. It has three P — P single bonds

d. It has four lone pairs of electrons

Choose the correct option

1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)