${\mathrm{PbO}}_2$ on reaction with ${\mathrm{HNO}}_3$ gives gas:

1. ${\mathrm{NO}}_2$

2. ${\mathrm{O}}_2$

3.  ${\mathrm{N}}_2$

4.  ${\mathrm{N}}_2\mathrm{O}$

AlF₃ is soluble in HF only in the presence of KF due to the formation of:

The correct statement among the following is :

An element that cannot form ${\mathrm{MF}}_6^{3-}$ ion is-

The correct order of atomic radii of the group 13 elements is-

1. B < Al < In < Ga < Tl
2. B < Al < Ga < In < Tl
3. B < Ga < Al < Tl < In
4. B < Ga < Al < In < Tl

In which of the following pairs, both the species are not isostructural?

1. \(\mathrm{SiCl}_4, \mathrm{PCl}_4^{+}\)
2. Diamond, silicon carbide
3. \(\mathrm{NH}_3, \mathrm{PH}_3\)
4. \(\mathrm{XeF}_4, \mathrm{XeO}_4\)
 

The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence?
1. Ga < ln < Al < Tl
2. Al < Ga < ln < Tl
3. Tl < ln < Ga < Al
4. ln < Tl < Ga < Al

A compound among the following having a similar structure to graphite is:

1. B
2. B₄C
3. B₂H₆
4. BN

Which of these is not a monomer for a high molecular mass silicone polymer?

The basic structural unit of silicates is:

1. SiO₄^4–

2. SiO₃^2–

3. SiO₄^2–

4. SiO