Question
In which of the following arrangements, the sequence is not strictly according to the property written against it?
A.
$$HF < HCl < HBr,HI:$$ increasing acid strength
B.
$$N{H_3} < P{H_3} < As{H_3} < Sb{H_3}:$$ increasing basic strength
C.
$$B < C < O < N:$$ increasing first ionization enthalpy
D.
$$C{O_2} < Si{O_2} < Sn{O_2} < Pb{O_2}:$$ increasing oxidising power
Answer :
$$N{H_3} < P{H_3} < As{H_3} < Sb{H_3}:$$ increasing basic strength
Solution :
In hydrides of $${15^{{\text{th}}}}$$ group elements, basic character
decreases on descending the group i.e.
$$N{H_3} > P{H_3} > As{H_3} > Sb{H_3}.$$