Why pbcl2 is more stable than pbcl4
Answers
Explanation:
Pb has 2 electrons in s orbital while 2 electrons in p orbital . So s electrons are inert and can not be removed and give valency of 4. Hence Pb forms 2 ions instead of 4 and PbCl2 becomes stable.
Assertion: PbCl
2
is more stable than PbCl
4
The inert pair effect is the tendency of the two electrons in the outermost atomic s orbital to remain unionized or unshared in compounds of post-transition metals., out of which (Pb) lead is one. The term inert pair effect is often used in relation to the increasing stability of oxidation states, that are two less than the group valency for the heavier elements of groups 13, 14, 15 and 16.
The s electrons are more tightly bound to the nucleus and therefore more difficult to ionize.
Due to inert pair effect, the higher oxidation state of an element is not stable as we move down the group.
In other words, Pb
+4
is less stable than Pb
+2
, hence PbCl
4
is also less stable.
Reason: PbCl
4
is a powerful oxidizing agent.
As we go down in a group 14 elements of periodic table, we observe that +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect. So, the outermost s-orbital electrons show reluctance to take part in the reaction. This leads to greater stability of +2 oxidation state in group 14 elements.
Instead of losing 4 electrons[2 electrons from S and 2 from P orbitals}, they tend to lose the p orbitals electrons, hence Pb
+4
can easily gain 2 electrons to form more stable Pb
+2
ions.
Pb(lead) show +2 oxidation state and easily gets reduced and therefore oxides others
Hence PbCl
4
is the stronger oxidizing agent.