Choose the pairs of isoelectronic compounds which are isostructural:

1. TeF₂, XeF₂

2. IBr₂^-, XeF₂

3. IF₃, XeF₂

4. BeCl₂, XeF₂

In which pair of ions both the species contain S-S bond?

1. ${\mathrm{S}}_2{\mathrm{O}}_7^{2-},$ ${\mathrm{S}}_2{\mathrm{O}}_8^{2-}$

2. ${\mathrm{S}}_4{\mathrm{O}}_6^{2-},$ ${\mathrm{S}}_2{\mathrm{O}}_3^{2-}$

3. ${\mathrm{S}}_4{\mathrm{O}}_6^{2-},$ ${\mathrm{S}}_2{\mathrm{O}}_7^{2-}$

4. ${\mathrm{S}}_2{\mathrm{O}}_7^{2-},$ ${\mathrm{S}}_2{\mathrm{O}}_3^{2-}$

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. 

The product obtained as a result of a reaction of nitrogen with CaC₂ is:

1. CaCN         

2. CaCN₃

3. Ca₂CN       

4. CaCN₂

The correct statement about given acids is: