So how do you know when a chemical is an acid or not? I know that an

[Titandwedebil]

So how do you know when a chemical is an acid or not? I know that an acid is a compound that, when dissolved, yields H atoms, but does that mean than any compound with H in it is (or has the potential to be) an acid?

For example:

HNO2, I put down that it was Hydrogen Nitrite, but the actual answer is Nitrous acid. How do I know whether or not to name it as an acid?

 

[Bloodthunder]

Calling HNO2 as hydrogen nitrite is not wrong (likewise, we can call HCl as hydrogen chloride). I suppose it is only when the substance, that has the description of an acid, is in water (aqueous) do we call it an acid.

I suppose you would just have to remember which are acids and which aren't. Usually, whatever inorganic compound has a hydrogen atom, or compounds with SO3H and COOH are acids. Can't remember others. =P

 

[Chem.Stud.]

There are several different definitions of acids. Brønsted being one guy who defined an acid as a substance that loses/gives/donates H+ (proton donor). Lewis is another one, and defines acid as a substance that is an electron-pair acceptor.

There probably are other definitions as well. And let's not forget the organic functional group
-COOH.

 

[bernabee4]

I think the lewis definition is the best since the other definitions can be explained by the accepting of electrons