 Just to have a quick look at an example, sulfuric acid and zinc, so sulfuric acid has the formula H2SO4 and in solution with solid zinc. We would have hydrogen gas as we know that's one of our products and the other product is the salt and so the salt is going to come from the metal and the anion. So in this case it's going to be zinc sulfate. Now the sulfates are NAG SAG so S for sulfates and there are two groups of exceptions for the sulfates both our LMS and our castor bear and zinc isn't either of those so this is going to be an aqueous salt. That means we can again look at a net ionic equation so we've got 2H+, you should just double check that it's balanced and in this case it is SO4 2 minus and ZN solid forming H2 gas ZN2 plus and SO4 2 minus. As we saw before the anion is the spectator ion in this case so what we've got is a displacement reaction occurring as the zinc solid displaces the hydrogen ions from the solution causing them to be released as a gas and the zinc taking its place in the solution. As I mentioned at the beginning of this video there are some exceptions to the rule when the concentration of the acid is high but there are some things we might explore just as an alternate pathway during class time. Thanks very much for watching.