EXPLAIN THE BASICITY AND STABILITY OF GROUP 1 AND GROUP 2 METALS ?

ANS :  Basicity increases down the group
            Stability decreases down the group of metal hydroxides
             LiOH < NaOH < KOH < RbOH < CsOH 
Reason 1- By ionisation enthalpy (I.E)
As I.E. decreases down the group , breaking of  M-OH bond becomes easy and more -OH  ions releases in the solution which increase the basic nature .
Reason 2- By HSAB PRINCIPLE ( HARD SOFT ACID BASE THEORY )

 small cation +small anion  or big cation + big anion
  reason  : small cation stabilize the small anion better and big cation stabilize the big anion better and forms strong bond.
weak bond is formed when
small cation + big cation  or big cation + small anion
Since -OH Anion is small anion so better stabilize by small Cation.

Basicity and stability order of group 1

FOR GROUP 2 METALS BASICITY AND STABILITY FOLLOWS THE SAME ORDER AND SAME REASONING

Basicity and stability order of group 2