Question

Which of the following statements is wrong? 

1) The stability of hydrides increases from NH₃ to BiH₃ in group 15 of the periodic table. 

2) Nitrogen cannot form pπ-dπ bond. 

3) Single N-N bond is weaker than the single P-P bond. 

4) N₂ O₄ has two resonance structures.

Answer 1

1) The stability of hydrides increases from NH₃ to BiH₃ in group 15 of the periodic table. 

Statement 1 is wrong because as we move from NH₃ to BiH₃ the size of the central atom increases and therefore, its tendency to form stable covalent bond with small hydrogen atom decreases. Thus M-H bond strength decreases and therefore stability decreases.