The elements of group 5A,the nitrogen family,form compounds with hydrogen having the boiling points listed below:

SbH₃ -17°C,AsH₃ -55°C,PH₃ -87°C,NH₃ -33°C.

The first three compounds illustrate a trend where the boiling point decreases as the mass decreases; however,ammonia (NH₃) does not follow the trend because of ___.

Question

Quizplus · Accepted Answer

The trend in boiling points for the compounds of group 5A with hydrogen is due to differences in the strength of the intermolecular forces between the molecules. The strength of intermolecular forces generally increases with increasing molecular mass. However, ammonia (NH₃) has a higher boiling point than would be expected based on its molecular mass alone because it can form hydrogen bonds with other ammonia molecules. Hydrogen bonding is a particularly strong type of intermolecular force, and it accounts for the higher boiling point of ammonia compared to the other 5A hydrides. Therefore, the correct answer is C) hydrogen bonding.

The Elements of Group 5A,the Nitrogen Family,form Compounds with Hydrogen