10) Explain which substance(s) would you expect to be a gas at standard
temperature and pressure (STP).
NI3
BF3
PC13
A) BF3
Its molecules are nonpolar and, therefore, are subject only to
dispersion forces.
B) NI3
Its molecules are polar and possess dipole-dipole interactions
therefore allowing them to exist as a gas.
C) PCL3
Its molecules are slightly polar and, therefore, possess dipole-
dipole interactions. However, they are weak enough to allow it
to exist as a gas.
D) Nlz and BF3
Both molecules are very light in mass. Therefore, they have
weak dispersion forces which causes them to be attracted very
weakly and exist as a gas.
