Stanton D. answered • 07/24/20
Tutor to Pique Your Sciences Interest
Hi Andrea G.,
Right away, without looking up any data, you should be able to say, the N2. Why? The molecule has no dipole moment, and no substantially exposed lone electron pairs. All the other molecules have either a permanent dipole or hydrogen bonding. Since these latter lead to much stronger attractive forces than the purely dispersive forces in N2, their bp's are higher. You should be able to speculate on other properties, too -- H2O2 is a substantial oxidant, important in these COVID-19 times (a vapor bath of H2O2 is a sterilant, although peroxyacetic acid drench is more commonly used for pervious surfaces); NBr3 is a probable nerve gas (NCl3 is the most toxic molecule from NaOCl + NH4OH reaction; the less chlorinated products are still strong lung irritants); H2S is also extremely toxic, but has odd physiological properties as it shuts down the electron transport chain -- with careful treatment, lab animals can enter a near-death state, but be revivable with fresh air and CPR. Too much H2S, though, and it's irreversable! So if you ever smell rotten-egg odor, immediately leave the area, even if you stop smelling it -- it knocks out your sense of smell at levels slightly above the smelling detection limit; CBr2H2 (standard writing = CH2Br2 ) is likely anaesthetic, the Freons do that but also can stop the heart at quite low levels, this was a problem noted in early human trials of such materials as propellants for inhalers ....
-- Cheers, -- Mr. d
