Let's take a look at the reaction of metals with acids. Here we have some magnesium reacting with hydrochloric acid. You can see there's some fizzing going on which means a release of gas and that's how the reaction looks if you see it for real. If we did an animation of this reaction here is a strip of magnesium going into some hydrochloric acid and as it goes in it reacts, releases gas and if there's enough acid the magnesium will react till it's all gone. So there the reaction has completed.
We can write a word equation for this reaction. Magnesium plus hydrochloric acid gives magnesium chloride and hydrogen which is a gas. Now we can write what's called a general equation to show what happens when any metal reacts with acid. So we've got metal plus acid gives salt and hydrogen.
In the equation above the metal is magnesium, the acid is hydrochloric acid, the type of salt we have is called magnesium chloride and there at the end we have hydrogen gas being given off. So this is a general equation and it's quite important to remember this so it's worth highlighting so I'm just going to put a box around it and give it a highlight there and we can remember this by using the word mash metal plus acid gives salt and hydrogen that's just a memory trigger to help you remember that general equation. It's also important to remember some common acids and the types of salt they make.
So we have hydrochloric acid, which will make a type of salt called a chloride salt. We have sulfuric acid, and this will make a sulfate salt. And we have nitric acid, which will make a salt called something nitrate.
So this is quite important. important to remember and it will help us to predict the name of the salt that's produced when we have a certain metal reacting with a certain acid. So let's keep that on the screen and have a look at an example of how we might use this.
So let's just move that out the way slightly. Now how can we use this? Well let's take a look at the example of reacting calcium metal with hydrochloric acid. Now using the information and above the equation we can see that hydrochloric acid will produce a salt that is a chloride salt.
So we know a chloride salt is going to be produced and we know hydrogen gas is going to be produced. So we can add that to our equation, something chloride plus hydrogen. What exactly is the name of the salt?
Well we can take the calcium from our reactants, the things that are reacting, and that becomes part of the salt. So we have calcium chloride plus hydrogen. Let's look at another example.
We've got magnesium plus sulfuric acid. In a similar way, sulfuric acid will make a sulfate salt when it reacts. So we know that we're going to have something sulfate, a sulfate salt and hydrogen gas.
And again, the magnesium will come from the reactant that reacted, the substance that reacted with the sulfuric acid. So we have magnesium sulfate and hydrogen gas. Let's see another example. Copper.
plus nitric acid and if you're getting the hang of this you'll see that it's a nitrate salt that's produced with hydrogen gas so we have copper nitrate plus hydrogen. Now let's make it slightly trickier let's take away the names of the common acids and salts and try magnesium plus nitric acid so pause here and give that a go and you should have got magnesium nitrate plus hydrogen. Now let's get rid of the general equation as well and have a look at a few different examples. So we've got copper plus hydrochloric acid, zinc plus sulfuric acid and for the last two we've got the products but not the two things that are reacting so you've got to work backwards from the products. So again pause here give that a go and we'll go through the answers in a moment.
So we have copper chloride plus hydrogen for number two, we have zinc sulfate plus hydrogen for number three for number four the two reactants were magnesium and sulfuric acid and for number five the two reactants were iron and nitric acid so hopefully you got those if not do have a look at the information in the video one more time but if you did okay you would have got all those correct if you got the hang of it and the final thing then to remember is that we should remember the general equation metal plus acid is or gives salt plus hydrogen and the common acids that we work with in science are hydrochloric sulfuric and nitric and those are the types of salts produced by each of them. So definitely worth making a note of what's on the screen here but other than that remember this is the science break we have videos for GCSE science and for key stage 3 science as well so do have a look through and see what you make of those but other than that thanks for watching and I'll see you soon.