Question #e2a78

1 Answer
Jul 19, 2015

Because they are the same chemical compound.

Explanation:

If I understand your question correctly, hydrogen chloride, or HCl, and hydrochloric acid, or HCl, have the same chemical formula because they are the same compound.

In essence, a hydrogen chloride molecule is formed when a hydrogen atom and a chlorine atom form a covalent bond.

![www.zoozo.org](useruploads.socratic.org)

The fact that chlorine is more electronegative than hydrogen ensures that this bond is actually a polar covalent bond, meaning that the bonding electrons spend more time surrounding the chlorine atom than they do the hydrogen atom.

Now, there is a subtle difference between hydrochloric acid and hydrogen chloride

When the molecule is in a gaseous state, it is called hydrogen chloride.

HCl_((g)) -> color(green)("hydrogen chloride")

When it is placed in aqueous solution, the compound is called hydrochloric acid.

HCl_((aq)) -> color(blue)("hydrochloric acid")

So basically, the HCl molecule goes by different names depending on which state it is in

  • in gaseous state -> hydrogen chloride;
  • In aqueous solution -> hydrochloric acid.