Question

Which of the following gases is the least likely to behave ideally?

• A. $He$
• B. $N_2$
• C. $HCl$
• D. $H_2$

Answer 1

Answer: (C)

$HCl$

HCl, because the bond between the two atoms is ionic therefore highly polar. H donates an electron to rid itself of valence electrons and Cl accepts the electron to complete it's Argon-like valence. Each atom has an 'ideal' valence independent of each other so they can dissociate more easily.

He acts ideally because it is an ideal (noble) gas.

$N_2$ and $H_2$ achieve 'ideal' valence by sharing valence electrons. This type of bond is very strong. Nitrogen's covalent bond is so strong that it is nearly inert even at temperatures over 1000°F.

Correct option is C