Question

Select the correct statement about elements of group 15:

• A. The order of stability of oxidation state for +3 is $B{i}^{3+}>S{b}^{3+}$ and for +5 is $B{i}^{5+}<S{b}^{5+}<A{s}^{5+}$
• B. In the case of nitrogen, all oxidation states from +1 to +4 tend to disproportionate in acid solution
• C. There is a considerable increase in covalent radius from N to P but from As to Bi only a small increase in covalent radius is observed.
• D. All of these.

Answer 1

Answer: (D)

All of these.

As we move down the group, lower oxidation state become stable due to inert pair effect.

The inertness of s subshell electrons towards the bond formation is called inert pair effect or it can be said as the inactiveness of electrons present in outermost shell (i.e. unpaired and involve in bond formation is called inert pair effect.

for example:

1) In 13th group, thallium can exhibit +1 and+3 oxidation states but it is stable in +1 oxidation state only due to inert pair effect

2) In 14th group , lead shows both +2 and +4 oxidation states but it is stable in +2 oxidation state due to inert pair effect.
so,order of stability of oxidation state for +3 is $B{i}^{3+}>S{b}^{3+}$ and for +5 is $B{i}^{5+}<S{b}^{5+}<A{s}^{5+}$.

Also, there is a considerable increase in covalent radius from N to P but from As to Bi only a small increase in covalent radius is observed due to inert pair effect.