TlCl more stable thanTlCl3

Why is TlCl more stable than TlCl3 molecule?

‘Tl’ is a group 13th or p-block heavier element. The outer electronic configuration of thallium is, [Xe] 4f14 5d10 6s26p1.

From the electronic arrangement of Tl, it has been found that, the valence electron of thallium element is 3.

So, the oxidation state of Tl should be +3 . But it has been found that , +3 oxidation state of Tl is less stable than+1 state.

Because, ‘Tl’ contained inner ‘d’ or ‘f’ electrons.

Now, due to poor shielding effect of ‘d’ or ‘f’ orbitals, the effective nuclear charge on outer most ‘ s’-electrons act strongly.

Since +3 oxidation state of Tl is less stable than +1 oxidation state, so TlCl is more stable than TlCl3 molecule.

Why is PbO2 act as a strong oxidizing substance ?

The outer electronic configuration of lead is, [Xe] 4f14 5d106s26p2.

From the electronic arrangement of lead, it has been found that, the valence electron of lead is 4. So, the oxidation number of lead should be +4 .

But it has been found that, the +4 oxidation state of lead is unstable than +2, due to inert pair effect.

For this reason, PbO2 or Pb(IV)oxide act as a strong oxidizing substance.

PbO2 is so strong oxidizing that, it can oxidized even concentrated sulfuric acid, PbO2 is so strong oxidizingnitric acid and hydrochloric acid.

Why Po(VI) compound act as a strong oxidizing substance ?

The outer electronic configuration of polonium is, [Xe] 4f14 5d10 6s26p4.

So, the maximum oxidation state of polonium may be +6. But, it is very unstable oxidation state.

Because, the outer ‘6s’-electron of polonium have no tendency to participate in chemical reaction due to inert pair effect.

Hence, Po(VI) compound act as a strong oxidizing agent in inorganic chemistry.

For this purpose, Po(VI) compound [ PoF6 ] act as a strong oxidizing substance.

Why is the melting point of ‘Sb’ and ‘Bi’ elements less than ‘As’ element ?

The melting point of ‘Sb’ and ‘Bi’ elements are less than ‘As’ element.

Becauseof the inertpair effect, the ‘Sb’ and ‘Bi’ elements form three covalent bond instead of five.

So, in ‘Sb’ and ‘Bi’ elements, the inter-atomic force of attraction become less than that of expected.

Hence the melting point of ‘Sb’ and ‘Bi’ elements is less than ‘As’ element.

· Why is PbO2 act as a strong oxidizing substance ?

· Why Po(VI) compound act as a strong oxidizing substance ?

· Why is the melting point of ‘Sb’ and ‘Bi’ elements less than ‘As’ element ?

Originally published at https://chemisfast.blogspot.com.