Identify the incorrect statements about group 15 elements : Choose the correct answer from the options given below :
- (A), (C), (E) only
- (D) and (E) only
- (A), (B), (D) only
- (B), (D), (E) only
Answer
(2) (D) and (E) only
Solution
(A): the N≡N bond enthalpy is very high (941.4 kJ mol-1), so N2 is inert at room temperature; (A) is correct.
(B): with ns2np3 the common oxidation states are −3, +3 and +5; (B) is correct.
(C): small size and high electronegativity let N form p - p bonds (N≡N); (C) is correct.
(D): due to the inert pair effect the +5 state becomes less stable down the group ( Bi5+ is a strong oxidant); (D) is incorrect.
(E): N has no d orbitals, so its maximum covalency is 4 (as in NH4+); (E) is incorrect.
Hence the incorrect statements are (D) and (E).
Answer: (2)