Question

Which of the following order is wrong?

• A. $N{H}_3<P{H}_3<As{H}_3$: acidic nature
• B. $L{i}^{+}<N{a}^{+}<K^{+}<C{s}^{+}$: ionic radius
• C. $A{l}_2{O}_3<MgO<N{a}_{2}O<K_{2}O$: basic
• D. $Li<Be<B<C$: ionization potential

Answer 1

The correct option is D $Li<Be<B<C$: ionization potential

A) Acidic nature depends on elecronegativity. In the periodic table, the trend in E.N is $N>P>As$.Thus the trend in acidic nature is reverse of that of E.N and can be written as ; $As{H}_3>P{H}_3>N{H}_3$
B) Ionic radii increases on moving down a group from top to bottom ,therefore the trend in ionic size is; $C{s}^{+}>K^{+}>N{a}^{+}>L{i}^{+}$
C) The trend in basicity is ; $A{l}_2{O}_3<MgO<N{a}_{2}O<K_{2}O$
D) Ionisation potiential increases on moving from left to right in a period.But first I.E of Be is more than B ; because Be has stable fully filled Valence orbital($2s^2$) Therefore the trend in I.E is ; $C>Be>B>Li$