A brown ring formed in the ring test for ${\mathrm{NO}}_3^{-}$ ion 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

Bismuth is present in a +5 oxidation state in: 

1. \(\mathrm{Bi}_{2} \mathrm{O}_{5}\)
2. \(\mathrm{BiF}_{5}\)
3. \(\mathrm{BiCl}_{5}\)
4. \(\mathrm{Bi}_{2} \mathrm{~S}_{5}\)

Ammonium dichromate and barium azide on heating gives: 

The number of  moles of NO produced by the oxidation of two moles of NH₃ will be -

1. 2

2. 3

3. 4

4. 6

The oxidation state of the central atom in the anion of compound \(\mathrm{NaH}_2 \mathrm{PO}_2\) will be:

A compound that does not have a tetrahedral shape is:

1. \(\mathrm{NH}_{4}^{+}\)
2. \(\mathrm{SiCl}_{4}\)
3. \(\mathrm{SF}_{4}\)
4. \(\mathrm{SO}_{4}^{2-}\)

Which of the following are peroxoacids of sulphur?
1. \(\mathrm{H}_{2} \mathrm{SO}_{5} \text { and } \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{8}\)
2. \(\mathrm{H}_{2} \mathrm{SO}_{5} \text { and } \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{7}\)
3. \(\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{7} \text { and } \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{8}\)
4. \(\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{6} \text { and } \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{7}\)

In the preparation of compounds of Xe, Bartlett had taken \(O_{2}^{+}PtF_{6}^{-}\) as a base compound. This is because: 

1. Both ${\mathrm{O}}_2$ and Xe have same size.

2. Both ${\mathrm{O}}_2$ and Xe have same electron gain enthalpy.

3. Both ${\mathrm{O}}_2$ and Xe have almost same ionisation enthalpy.

4. Both Xe and ${\mathrm{O}}_2$ are gases.

Which of the following is true regarding the P₄ molecule of white phosphorus?

1. It has 6 lone pairs of electrons.

2. It has four P — P single bonds.

3. It has three P — P single bonds.

4. It has four lone pairs of electrons.

The correct statement among the following about SO₂ gas is: