Consider the boiling points of the following molecules. They all have the same m
ID: 878528 • Letter: C
Question
Consider the boiling points of the following molecules. They all have the same molecular shape. Molecule Boiling Point (K) NH3 240 PH3 186 AsH3 210 SbH3 256 Which of the following statements are true? 1) All four molecules have dipole moments. 2) Only NH3 has a dipole moment. 3) SbH3 has the highest boiling point because is has a very high molecular weight which allows for very strong dispersion forces. 4) Even though NH3 is the lightest and has the smallest dispersion forces, it has a higher boiling point than all but the heaviest molecule in the list, SbH3, due to hydrogen bonding. 5) SbH3 has the highest boiling point because it has ion dipole interactions. A.1,3,4 B.1,2,4,5 C.2,3,4 D.1,2,3,5 E.3,4,5Explanation / Answer
option (A) 1,3,4
All molecules have dipolemoment due to no symmetry. Structure of all molecules is trigonal pyramidal.
B.Pt is proportional to molecular weight due to higher magnitude of dispersion forces.
NH3 B.pt is more due to intermolecular H-bonding. Hence, its boiling point point is higher than all other except SbH3.