JEE MAIN - Chemistry (2011 - No. 21)
Which of the following statement is wrong?
Nitrogen cannot form $$d\pi - p\pi$$ bond.
Single N – N bond is weaker than the single P – P bond
N2O4 has two resonance structures
The stability of hydrides increases from NH3 to BiH3 in group 15 of the periodic table
Explicación
The case of formation and stability of hydrides decreases rapidly from $$N{H_3}$$ to $$Bi{H_3}.$$. This is evident from their dissociation temperature which decreases from $$N{H_3}$$ to $$B{H_3}.$$ As we go down the group the size of central atom increases and thus metal-hydrogen bond becomes weaker due to decreased overlap between the large central atom and small hydrogen atom.
$$\mathop {N{H_3} > }\limits_{(most\,\,stable)} P{H_3} > As{H_3} > Sb{H_3}\mathop { > Bi{H_3}}\limits_{(least\,stable)} $$
$$\mathop {N{H_3} > }\limits_{(most\,\,stable)} P{H_3} > As{H_3} > Sb{H_3}\mathop { > Bi{H_3}}\limits_{(least\,stable)} $$