Hello, my name's Mrs. Clegg.

Welcome to today's lesson on the chemical reactions of acids and metals and metal carbonates.

We're gonna look at the activity series and find out which metals react easily with dilute acids and which ones don't.

This lesson is part of the Making Salts unit.

So let's get started.

By the end of today's lesson, you should feel much more comfortable about being able to write balanced equations for acid and metal reactions as well as acid and metal carbonate reactions.

And you should be able to predict the names and the state of products.

Here are today's keywords that I would like you to listen out.

For balanced equations and state symbols.

So a balanced equation is a reaction using a symbol equation with coefficients which ensure there are equal number of atoms of each element on both sides of the symbol equation.

And then the state symbol, these are used in chemical equations to indicate the physical state of a substance.

Today's lesson is divided into two parts: reactions of acids and metals, and the reactions of acids and metal carbonates.

So let's get started on the first part.

A metal reacting with an acid produces a soluble metal salt, hydrogen gas, we often see that as bubbles in the reaction solution, and here's the general equation for a reaction of a metal with acid.

So a metal plus acid combine to form metal salt plus hydrogen gas.

Let's just refresh our minds as to how the metal salt gets its name.

So magnesium is the metal and that goes as the first part of the metal salt's name, magnesium, and then the acid, the nitric bit becomes nitrate and the end of the metal salt name.

Let's have a quick check.

So what is the general equation for a reaction between a metal and an acid? Well done if you said B, metal plus acid forms a metal salt and hydrogen.

Now, different acids produce different types of metal salts.

So we've got the name of the acid, the name of the metal salt ending, and the chemical formula of the acid.

So you can see hydrochloric acid would give us a metal salt ending of chloride.

So here's an example.

Magnesium plus acid gives us magnesium fluoride and hydrogen.

So magnesium and hydrochloric acid.

What about this one? Iron plus sulfuric acid gives iron sulphate and hydrogen.

So the iron forms the first part of the metal salt and the sulfuric forms the last part, iron sulphate.

In chemical equations, you can identify the state of matter of each substance.

And when you using the symbol equation, you definitely should use them.

The states of matter just to remind ourselves are solid, liquid, gas.

And of course, when it's in solution, we put aqueous.

The balanced symbol equations for the reactions of acids and metals are written as follows.

So the formula for hydrochloric acid is HCl and then in brackets aqueous.

And sulfuric acid H2SO4 aqueous.

Nitric is HNO3, again aqueous.

So let's have a look at a specific example.

We use magnesium again.

So magnesium and hydrochloric acid form magnesium chloride and hydrogen.

So here's the symbol equation.

So the metal forms the first part of the salt and then the acid forms the second part.

And don't forget the state symbols.

And the hydrogen gas is coming from the hydrogen ions from the hydrochloric acid.

Let's have a look at iron and sulfuric acid again then.

So the metal iron and sulfuric acid from iron sulphate and hydrogen gas, so we can see where the metal comes from and where the sulphate comes from and where the hydrogen gas comes from.

Let's have a quick check.

So is this true or is this false? Have a look at the equation and decide what you think.

Well done if you said false and can you justify your answer? Choose one of these statements.

Great if you said A, sulfuric acid and metals react to form metal sulphates and hydrogen.

So we could correct that equation to be zinc plus sulfuric combine to form zinc sulphate and hydrogen.

Let's have a look at another question.

So which is the correct symbol equation for the reaction between zinc and sulfuric acid, which produces zinc sulphate and hydrogen gas? So the way that I work out is actually I'm looking to see that it's zinc and sulfuric acid on the left-hand side of the equation and they're all correct, they're all the same.

And so if I move to the product side of the equation, I can see that B cannot be correct, that's not zinc sulphate.

So if we look at A, we're producing water, so it's not that one.

It's got to be C.

Well done if you got those correct.

The chemical test for hydrogen gas is to introduce a lit splint and it makes a squeaky pop.

So we're going to have a quick look at a video in a moment, but first of all, I'll show you what's going to happen.

We add metal to the acid in a test tube and then we hold an empty test tube over the top for about 30 seconds.

And then we ask a partner to hold a lit splint near the test tube opening and we listen for the squeaky pop.

Let's watch this in progress.

<v Presenter>Okay, so this is magnesium</v> and the hydrogen pop.

<v Instructor>So you can see the reaction</v> between magnesium and the acid there.

Lots of effervescence or bubbling.

(solution bubbling) (loud squeaky pop) <v Presenter>Squeaky pop.

</v> <v ->So quick check, what's the chemical test for hydrogen gas?</v> Well done if you said C, we're listening for this squeaky bop test, aren't we, when the hydrogen is exploding.

The top one is the test for oxygen.

The second one, part B, is the test for carbon dioxide gas.

And part D, we would use that potentially to see if it was chlorine gas.

Most reactions between acids and metals are exothermic and cause an increase in temperature.

So remember the definition of an exothermic reaction is one that transfers energy to the surroundings and so the temperature of the surroundings increases.

You can often feel the temperature increase through the test tubes or you can actually measure it using the thermometer.

The way that metals react with acids varies, and it depends on the reactivity series.

So here's the reactivity series, you might have seen this before.

Potassium, sodium, calcium there towards the top, and copper, silver, gold, and platinum towards the bottom.

Metals react with acids depending on their reactivity and the concentration of the acid.

Now if we take dilute acids, those that have got fewer hydrogen ions, the unreactive metals, the copper, the silver, the gold, the platinum, they pretty much do not react with them.

All metals will react with concentrated acids, those who have got many more hydrogen ions.

We can compare the reactivity of metals with acid by looking at three things.

We can look at the rate of bubble formation or effervescence.

And if we look at the test tube there, it's got magnesium and acid in, we can see the bubbling being given off.

You could measure the temperature of the reaction mixture and it might increase if it's an exothermic reaction.

And you can also observe the corrosion of the metal, how much is worn away and reduces in size over the time of the reaction.

Let's have a quick check.

So which of the following indicate a reaction has taken place between an acid and a metal? Well done if you said effervescence/bubbles forming and also metals would corrode.

The temperature is going to increase because it's an exothermic reaction.

Which here is the most reactive metal? Well done if you said A, it's got the most bubbles, most effervescence.

Let's have a look at task A.

So magnesium is a reactive metal, as we know, and a small piece was placed with dilute sulfuric acid in a test tube.

So we got a series of questions there to complete.

Have a read of those, pause the video and come back when you've had a go at all of them.

Welcome back.

How did you do? Let's have a look.

So what would you expect to see? If we have a look at the clip there, you would expect to see bubbling or effervescence as hydrogen is produced.

And towards the end of it, you might be able to see that the metal had corroded, it had worn away.

If you held the test tube, you would expect the test tube to feel warm because this is an exothermic reaction and energy is released to the surroundings.

Let's have a look at C and D now.

So part C, you have to describe a test to confirm one of the products.

So the test that we've looked at is the test for hydrogen.

So you put an upside down or an inverted test tube, over the mouth of the test tube the reaction was occurring in, and collect the gas that's produced.

You'd wait 30 seconds to a minute while the reaction occurs to collect the gas, and then you would insert a lit splint into the inverted test tube and you'd hear a squeaky pop.

You might not have written exactly the same, but hopefully you've got all those points.

And then an equation for the reaction.

So magnesium plus sulfuric acid combine to form magnesium sulphate and hydrogen gas.

And we've got the correct state symbols there.

Let's have a look at part E.

The same experiment was repeated using copper.

Describe any of the differences you might observe and why.

So remember this was dilute sulfuric acid, copper is unreactive, and therefore there would be no reaction with the dilute sulfuric acid.

No bubbling would be seen as no gas is produced.

The test tube wouldn't become warm as there's no energy being transferred, and the piece of copper would not corrode.

Well done if you've got all of those correct.

Let's have a look at question two now.

So I want you to write the balanced symbol equations for the following reactions of dilute acid with metal.

Remember to consider their reactivity and I've given you the reactivity series there to help.

So pause the video and come back when you've completed them.

Okay, welcome back.

Let's have a look.

How did you do? So there's the equation for part A.

Part B, silver is right down there towards the bottom of the reactivity series and it's a dilute sulfuric acid, so there would be no reaction.

Zinc is sort of middle of the reactivity table, so there would be a reaction, and calcium too.

Let's move on to the second part of our lesson today.

Metal carbonates consist of metal and carbonate ions.

A carbonate ion consists of one carbon with three oxygen atoms bonded together.

And zinc carbonate, the formula there would be zinc and there's the carbonate group.

So which compound has or have the correct chemical formula for carbonates? Have a look and see what you think.

Well done if you said A, that would be calcium carbonate, and C potassium carbonate.

Now, calcium carbonate is a very common carbonate and it's the main compound in chalk and marble.

You might have seen or heard about the white cliffs of Dover and they're white 'cause they're made of calcium carbonate.

Statues are often made from marble, which is calcium carbonate as well.

And we often have limestone walls which contain calcium carbonate.

When acids react with metal carbonate, we get the following reaction.

So acid plus metal carbonate combine to produce salt plus water plus carbon dioxide gas.

And let's look at a specific example now.

So hydrochloric acid plus copper carbonate would give us copper chloride plus water plus carbon dioxide.

And let's have a look at those as a symbol equation.

And don't forget the state symbols.

Let's have a quick check.

Three products are produced when an acid reacts with a metal carbonate.

Is that true? Well done if you said true.

And can you justify your answer? Well done if you said B because carbon dioxide gas is produced.

Here we've got an example of calcium carbonate reacting with sulfuric acid, and you can see the carbon dioxide gas being produced as bubbles or effervescence.

Let's have a look at the word equation.

Sulfuric acid plus calcium carbonate produces calcium sulphate and water and carbon dioxide.

And then you should be able to convert that into the symbol equation, which is below.

Notice that the calcium carbonate is a solid, as you see it being put into the beaker there, it's a solid.

So don't forget the solid state symbol there.

Let's have a quick check.

What is the gas product produced when a metal carbonate reacts with an acid? Well done if you said carbon dioxide.

The type of metal carbonate and acid that we use will determine which metal salt we make.

So let's have a look at the table again.

So using hydrochloric acid would result in a chloride metal salt.

Let's have a look at an example.

So let's use copper carbonate and nitric acid.

So the name for the metal bit of the metal salt comes from the copper carbonate and the endings comes from the type of acid used, so copper nitrate.

Let's have a quick check.

Select the products which would be produced when potassium carbonate and sulfuric acid react together.

Have a read and we'll see you in a moment.

So when I look at these, I think the first one, potassium sulfuric, is not a proper compound, so I discount that one.

B looks promising.

C, sodium sulphate.

I'm not sure where the metal sodium came from, so it can't be that one.

And part D, we've got hydrogen being produced.

B is the correct answer.

Well done if you got that correct.

Let's have a look at another question.

Lead carbonate and nitric acid will produce lead nitrate, water, and carbon dioxide gas.

Is that true or is that false? Well done if you said true and can you justify your answer? Well done if you said A.

And of course, we can write balanced symbol equations for the reaction of carbonates and acids and remember to include the state symbols as usual.

So let's have a look at zinc carbonate and hydrochloric acid.

The word equation for that would be zinc chloride and water and carbon dioxide.

Let's look at the symbol equation.

And do a quick check to make sure it's balanced, which it is.

Metal carbonates are generally solids and they react with aqueous solutions of acid to produce soluble salts, water, and carbon dioxide gas.

Let's have a look at some more examples of carbonates reacting with acids.

So we've got iron carbonate and nitric acid forming iron nitrate, water, and carbon dioxide.

Here's the equation, iron from the iron carbonate, it transfers across to the metal salt, and the type of acid that we use, the nitric acid, gives us the ending, so iron nitrate.

Let's have a look at this one.

Tin carbonate and sulfuric acid.

If you haven't got a periodic table beside you, the symbol for tin is a large S, a capital S, and a small n like this.

So tin carbonate and sulfuric acid produce tin sulphate plus water plus carbon dioxide.

So again, the tin comes from the tin carbonate and the sulfuric acid gives us the ending of the metal salt.

Let's have a quick check.

So what's the chemical formula for the metal salt formed when strontium carbonate and hydrochloric acid react together? If we look at A, that looks like a possibility.

B, I'm not sure where Se comes from.

And C, that would be strontium sulphate, so it can't be that because we're using hydrochloric acid, therefore the answer must be A.

Well done.

When carbonates and acids react together, they produce bubbles of carbon dioxide gas.

And carbon dioxide gas, we can't smell it, it's got no odour, it's colourless, and we need some way of identifying it, so we can carry out a chemical test.

The equipment below is used to test for carbon dioxide gas.

First of all, we'd put some solid metal carbonate into the conical flask with the acid and the carbon dioxide that's produced bubbles through the limewater and we see what happens to the colourless limewater.

So the positive test for carbon dioxide gas would be that the limewater changes from being colourless to a cloudy white.

Some people call it a milky solution.

And the carbon dioxide basically has reacted with the limewater to produce a cloudy precipitate.

And this precipitate is calcium carbonate, which is a solid.

So here's the equation here at the bottom and notice the state symbol for calcium carbonate.

Now, when marble surfaces need to be cleaned, we should never use an acid-based product.

And if you put a piece of marble into a test tube containing hydrochloric acid, you will see that it bubbles and the marble gets smaller.

So explain what happened in the test tube.

Well done if you said C, a chemical reaction occurred and it formed a new soluble substance.

Let's have a go at task B.

So what I'd like you to do is correct the following symbol equations for the reactions of dilute acid with metal carbonates.

And I've got four examples there I'd like you to have a go at.

So there's various errors in here, so I'd like you to look at them very carefully and correct them.

Pause the video and come back when you've done all four.

Okay, let's see how you did.

So in part A, the first error is magnesium carbonate is not a liquid, it's aqueous.

And we were reacting sulfuric acid with magnesium carbonate, so I don't know why we've suddenly got zinc there.

So let's have a look at what the equation should be and see if you got those correct.

Let's have a look at part B.

We've got nitric acid and potassium carbonate and somehow we're making potassium sulphate there, but we were using nitric acid so that can't be correct, and we're making hydrogen so that's not right.

So the correct equation is this.

Let's have a look at part C.

So the first error I can see is that we haven't got calcium carbonate there.

The subscript number is wrong, so that needs changing.

And if you actually work out whether this equation is balanced or not, you will see that there's an error there in terms of the water.

So the correct equation should be this.

And then in the last one, we've got nitric acid and copper carbonate.

We've made copper nitrate and water and carbon dioxide.

So copper nitrate, that's not the correct formula for copper nitrate, so we need to check that.

And water is not aqueous, it's a liquid, so the correct equation is this one.

Absolutely amazing if you got all of those.

Well done.

Let's have a look at question two.

Draw and label the equipment required to test for carbon dioxide gas produced when an acid reacts with a carbonate.

Describe what you would see and give both the word and symbol equation for the test for carbon dioxide gas.

So pause the video and come back when you're ready.

Okay, let's have a look at your diagram.

So it would look something like this.

Remember we use straight lines, a pencil and a ruler.

We wouldn't normally colour in the bung and liquid, but that just makes it easier for you to see it on the screen.

And then you had to describe what you would see and give the word and symbol equation.

So let's have a look.

So describe what you would see.

You would see bubbles being produced.

And when these bubble through the limewater solution, it will turn from colourless to cloudy or milky white.

And then the word and symbol equation for the test for carbon dioxide gas is limewater plus carbon dioxide produces calcium carbonate, which is solid, and water.

Well done.

Limewater is calcium hydroxide.

So we've come to the end of the lesson now.

Let's have a quick look at our summary.

So these are the main learning points from today.

Acids react with metals and metal carbonates to form metal salts.

The metal salt formed will depend upon the acid that's used, so metal plus acid gives metal salt plus hydrogen gas.

If you remember, if you're using hydrochloric acid, the metal salt ending will be a chloride.

If you're using sulfuric acid, then the metal salt ending will be sulphate.

And if you're using nitric acid, it will be a nitrate that's formed.

We looked at the test for hydrogen gas, which was a lit splint that makes a squeaky pop.

And we had a look at a video demonstration of how to do this.

And then we looked at metal carbonates and how they reacted with acids.

And the general equation for the chemical reaction of acids with a metal carbonate is metal carbonate plus acid produces a metal salt plus water plus carbon dioxide gas.

The test for carbon dioxide gas is to bubble it through colourless limewater, which will turn cloudy if carbon dioxide is present.

If it stays colourless, then the gas is not carbon dioxide.

And we must use state symbols in all of our chemical equations to identify the state of the substances and we've been doing that throughout.

Well done.

We've learned a lot today.

I look forward to working with you in the future.