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 basic structural unit of silicates is:

1. SiO₄^4–

2. SiO₃^2–

3. SiO₄^2–

4. SiO

False statement regarding PCl₅ is:

The correct structure of tribromo octoxide is:

1.
2.
3.
4.

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

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

The incorrect statement among the following is -

1. ${\mathrm{PbX}}_2$ is more stable than ${\mathrm{PbX}}_4$

2. ${\mathrm{PbCl}}_4$ is less stable than ${\mathrm{SnCl}}_4$ but ${\mathrm{PbCl}}_2$ is more stable than ${\mathrm{SnCl}}_2$

3. ${\mathrm{PbCl}}_4$ is less stable than ${\mathrm{SnCl}}_4$

4. Pb(II) is a good reducing agent while Sn(II) is not

Which of the following statements is false? 

Aluminium chloride in acidified aqueous solution forms a complex 'A'.
The formula of A and hybridisation state of Al in 'A' is respectively:

1. [Al(H₂O)₆]³⁺, sp³d²

2. [Al(H₂O)₄]³⁺, sp³

3. [Al(H2O)4]3+, dsp2

4. [Al(H₂O)]³⁺, d²sp³