1
$\begingroup$

$$\ce{NH_3 + HCl -> NH_4Cl}$$

The electronic structure of ammonia is such so that the nitrogen atom has an outer shell with a lone pair of electrons.

When ammonia reacts with hydrochloric acid (above), the hydrogen from the $\ce{HCl}$ moves to the ammonia. However, it leaves its electrons behind because there is already a lone pair of 2 electrons on the $\ce{N}$ atom, allowing it to retain a $\mathrm{1s^2}$ shell.

Why doesn't the hydrogen take its electron over and nitrogen doesn't then "donate" an electron to the chlorine?

$\endgroup$
  • 3
    $\begingroup$ This is an acid base reaction : strong HCl acid with weak base NH3 and it's a neutralization. Here the Cl- is behaving as a spectator ion. $\endgroup$ – bonCodigo Jun 2 '15 at 10:54
2
$\begingroup$

Chlorine is the more electronegative species. It would thus retain the bonding electrons when the hydrogen is evicted. This hydrogen then forms a coordinate bond with the lone pair on nitrogen.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.