How To Identify Acid Reactions

Hi, I'm Donald Sinclair. I'm a science teacher with Greater London Tutors and today, we're going to be looking at a few topics in chemistry. This is how to identify acid reactions.

It's useful to be able to identify individual acids. I put a formula for a few of the most common ones on the board here. Sulfuric, Nitric and Hydrochloric acid.

The main thing to remember is that the chemical formula for an acid will always contain hydrogen or multiple units of hydrogen somewhere in the formula. So for example, sulfuric acid is simply a sulfate group attached to two hydrogens. Nitric acid is nitrate plus a hydrogen.

Hydrochloric is chlorine plus hydrogen. If something has a hydroxide group as opposed to hydrogen, that does not mean it's an acid. It's quite the opposite, it means it's a base.

So having identified the acids, we can look at some simple acid reactions. Acids react with metals or bases to form salts and other materials as well depending on what it is they're reacting with. So for an example, the acid and a metal is very simple, it produces a salt plus hydrogen gas.

So for example, hydrochloric acid will react with magnesium to form a salt called magnesium chloride as well as hydrogen gas. When you're naming a salt, it's very easy, remember that the salt will always be a metal bonded with a non-metal. So the metal will always be from the metal, obviously.

The non-metal will come from the name of the acid. If it's hydrochloric acid, it will be something chloride. If this reaction had sulfuric acid instead for example, then it would be magnesium sulfate instead, and so on and so forth.

Acids can also do that with bases. For example, oxides or hydroxides will react with acids to form a salt plus water. You have water now instead of hydrogen because the presence of oxygen.

So for example, sulfuric acid will react with copper oxide. That will produce a salt. Again we get the name of the salt from the compounds involved.

The metal comes from the oxide in this case copper and the non-metal in the salt comes from the acid. Sulfuric acid gives us copper sulfate plus water. If this was hydrochloric acid involved in this, copper chloride would be the salt in the end.

Finally, once extra case is when acid reacts with a carbonate. In this case, it's exactly the same as an oxide or hydroxide but because of the presence of carbon, we also get carbon dioxide as one of our products. So for example, hydrochloric acid will react with calcium carbonate to get the salt which is calcium chloride plus water plus carbon dioxide. .