Question

How can u explain higher stability of BCl3 as compared to TlCl3?

Answer 1

Tl has oxidation states of +1 and +3 in which +1 is predominant and +3 stability decreases as we go down the group

so Bcl3 is more stable when compared to TlCl3

Answer 2

Hey folk...

→In a grp  while coming down,

bcoz of  increase in size  and involvement of d and f orbital , the

 outermost ns2 electron  have ineffective sheilding by d or f orbital ,

 so, the s orbital electron remian paired and there increase a inert

pair effect , due to which s orbital electron are not used in bonding

and +1 oxidation state become more stable while +3 o.s doesno

t stable .


hence , first element boron show +3 o.s in bcl3 becomes stable while

 the last element of group thalium doesnot show a stable +3 o.s

so, bcl3 is stable while ticl3 is unstable . 

Thank you
HOPE IT HELPS..!