NEET2013Chemistryp Block Elements (Group 15, 16, 17 & 18)Actual
Which of the following is the increasing order of enthalpy of vaporization?
Options
- ANH ₃, PH ₃, AsH ₃
- BAsH ₃, PH ₃, NH ₃
- CNH ₃, AsH ₃, PH ₃
- DPH ₃, AsH ₃, NH ₃
Correct answer
D. PH ₃, AsH ₃, NH ₃
Step-by-step solution
The inter-particle forces are strongest in ( NH ₃ ) (Hydrogen bonds). In ( PH ₃ ) and ( AsH ₃ ) the inter-particle forces are dipole-dipole forces which are relatively stronger in ( AsH ₃ ). So the increasing order of vaporization is ( PH ₃, AsH ₃ ), and ( NH ₃ )