Question

Order of boiling points of group 15 and group 16 hydrides ?

Answer 1

Dear student ,
The b.p.order of group 15 elements is : BiH₃ > SbH₃ > NH₃ > AsH₃ > PH₃
Reason : first two have higher b.p. due to higher molecular mass while NH₃ has higher b.p. in spite of low mol. mass due to inter molecular H- bonding , bot this bonding could not increase the surface area up to large extent
For group 16 : H₂O > H₂Te > H₂Se > H₂S
Water has higher b.p. although it has lower mol. mass is due to showing stronger inter molecular H - bonding
Regards