Choose the pairs of isoelectronic compounds which are isostructural:

1. TeF₂, XeF₂

2. IBr₂^-, XeF₂

3. IF₃, XeF₂

4. BeCl₂, XeF₂

Which of the following reactions does not exhibit the oxidising behaviour of H₂SO₄?

1. Cu + 2H₂SO₄ → CuSO₄ + SO₂ + 2H₂O

2. 3S + 2H₂SO₄ → 3SO₂ + 2H₂O

3. C + 2H₂SO₄ → CO₂ + 2SO₂ + 2H₂O

4. CaF₂ + H₂SO₄ → CaSO₄ + 2HF

In the structure of ClF₃, the number of lone pairs of electrons on central atom 'Cl' is:

1. 1

2. 2

3. 3

4. 4

Match the compounds given in Column I with the  shape given in Column II and mark the correct option. 

Which of the statements given below is incorrect?

1. \(\mathrm{C l_{2} O_{7  }}\)${}_{}$is an anhydride of perchloric acid
2. \(\mathrm{O_{3}}\)${\mathrm{}}_{}$ molecule is bent
3. ONF is isoelectronic with \(\mathrm{N O_{2}^{-}}\)${}_{}^{}$ 
4. \(\mathrm{O F_{2}}\) is an oxide of fluorine

The variation of the boiling point of the hydrogen halides is in the order HF > HI > HBr > HCl. 
The higher boiling point of hydrogen fluoride is explained as:

The strong reducing behaviour of H₃PO₂ is due to:

1. Presence of one -OH group and two P-H bonds.

2. High electron gain enthalpy of phosphorus.

3. High oxidation state of phosphorus.

4. Presence of two -OH groups and one P-H bond.

The acidity of diprotic acids in aqueous solution increases in the order:

1. H₂S < H₂Se < H₂Te

2. H₂Se < H₂S < H₂Te

3. H₂Te < H₂S < H₂Se

4. H₂Se < H₂Te < H₂S