[Music] hi and welcome back to precise lesson wk by the end of this two-part video you should be able to describe our acids react with metals if you're a higher tier student you should then be able to identify which chemicals are oxidized and which chemicals are reduced in terms of electrons we're going to start by recapping acids there are three acids that we use a lot in chemistry these are hydrochloric acid sulfuric acid and nitric acid I'm showing the formula of each of these acids and there's been this - a key fact all acids contain hydrogen now in a previous video we looked at the reactivity series of metals and I'm showing you that here as you can see all of these metals are more reactive than hydrogen that means that these methods can displace hydrogen from acids and look at that now this shows the reaction between sulfuric acid and magnesium as you can see the magnesium has displaced or pushed out the hydrogen from the sulfuric acid so in this reaction we've made magnesium sulfate on hydrogen gas now scientists call substances such as magnesium sulfate assault so when acids react with metals we always make two products these are a salt and hydrogen gas so the question is how do we know which salt will produce well that depends on both the acid that were using and the metal that were reacting up with sort of look at this now the AQA specifications say that you could be asked about how to acids react with metals and these are hydrochloric acid and sulfuric acid hydrochloric acid produces salts that end in the word chloride so fewer custard produce of salt would end in the word sulfate and you really need to learn these fully examiner could be asked to describe have three different metals react with these two acids and these metals are magnesium zinc and iron so here's magnesium reacting with hydrochloric acid while making the salt magnesium chloride armed hydrogen gas and here we can see magnesium reacting with sulfuric acid to make the salt magnesium sulfate and hydrogen gas now magnesium reacts rapidly with acids and we can explain that by looking again at the reactivity series here it is as you can see magnesium is quite a lot more reactive than hydrogen this means that magnesium can easily displace hydrogen from acids so if we now look at the symbol equations for these reactions we can see the magnesium displacing the hydrogen from the acids and making hydrogen gas here's then Cree acting with hydrochloric acid in sulfuric acid this is quite a rapid reaction and again we can see why by looking at the reactivity series zinc is more reactive than hydrogen so it can quite easily displace hydrogen from acids here's our iron reacting with hydrochloric acid and sulfuric acid this is a fairly slow reaction looking at the reactivity series we can see that although I am is more reactor than hydrogen it's only slightly more reactive which means that this will be a slow reaction remember you'll find plenty of questions on the reactions of acids with metals in my vision workbook which you can get by clicking on the link above in the next video we're going to look at the reactions of metals with acid in terms of oxidation and reduction okay so hopefully now you should be able to describe how acids react with metals [Music]