P Block Elements

Phosphorus exists as while sulphur exists as . Hence, atomicity of phosphorus (i.e., 4) is half that of sulphur (i.e., 8).

Carbon has configuration of the valence shell, its most common oxidation state is Thus, shows oxidation state in its hydrides.

Oxyacids are the compounds which contains hydrogen and oxygen along with main element.
So, are the oxyacids of sulphur while is the oxide of sulphur.

Chlorine reacts slowly with to form and .
The . then decomposes into . and radicals.

These oxygen radicals are very strong oxidising as well as effective bleaching agent in aqueous solution of or hypochlorite salt.

When chlorine reacts with dilute and cold , sodium chloride and sodium hypochloride are formed.
(cold)
Let oxidation state of in is .

Let oxidation state of in
is



Oxidation states of chlorine changes from
to and

The relative strength of Lewis acids of boron trihalide increases in the order This can be explained on the basis of the tendency of the halogen atom to back donate its electron to the boron atom and makes it less electron deficient

Nitrogen monoxide (nitric oxide) is paramagnetic in nature due to one unpaired electron (total valence electrons). It can be represented by the following resonance structures .Nitrogen dioxide is also paramagnetic due to one unpaired electron. Its structure is as

Sulphurous acid contains a lone pair of electrons on sulphur. The structure of sulphurous acid is as

Due to lack of d-orbitals in , it is unable to form complex ion.

As the size of halogen increases from to , the bond dissociation energy decreases

Peroxodisulphuric acid

Sulphuric acid

Pyrosulphuric acid

Sulphurous acid

is strongest oxidising agent due to its low enthalpy of dissociation as bond is weak and high enthalpy of hydration of small ion

Answer (a) stability of higher oxidation state increases with the size