This quiz will assess you on knowledge learned in today's lesson, as well as what you have learned in earlier lessons.

What pH are acids?

What colour would an alkali turn universal indicator?

Pure water is pH 7. What does this tell us about pure water?

What is the general equation for a neutralisation reaction?

Which piece of equipment is used to perform a neutralisation experiment?

Hydrochloric acid + sodium hydroxide → sodium chloride + _________

Revision - which of the following is not an example of a salt?

Revision - if an atom contains 18 electrons in total, what is the electron configuration for that atom?

Neutralisation

﻿Hi everyone! It's Miss Fenner here. Welcome to the lesson. This is lesson number 10 in the reactivity topic. And we're going to be looking at how to write the perfect practical method. Before we get started, can you check that you've put your phone out of the way, and turned it on silent, and you're ready to learn. Make sure you give all of the activities in the lesson today a really good go. It's great revision, even if you've done a similar lesson before. Let's get going. So, here's the equipment you're going to need for the lesson today. An exercise book or some paper, and a pen or pencil. So if you haven't got that already, pause the lesson now, please, and go collect it. So, we're on lesson 10, and we're going to be looking at method writing. Now, method writing is the title for today's lesson. So, if you haven't already written that down, can you do that now please? We're going to start off by looking at a math of the making of salt. Then, we're going to plan a similar experiment together. And finally, you'll have a go at writing a method for one of these practicals yourself. How to make a salt. So far in this reactivity topic, we've looked at four different ways that we can make salts. We've looked at four different general equations, used to make salts. The first was reacting a metal and an acid, so we know if you react a metal and an acid, you'll form a salt and hydrogen. Alternatively, we could make a salt by reacting a metal carbonate and an acid, and we'll form the salt, water, and carbon dioxide. Or, we could react a metal oxide and acid, to form a salt and water. And finally, we could also react an alkali and an acid, to form a salt and water. So, any of these four general equations result in a production of a salt. And we can use different reactions, different reactants, to produce the same salt. Let's have a look at this. For example, if I wanted to make the salt sodium chloride, I could react sodium with hydrochloric acid. And that will give me sodium chloride. That will give me the salt, sodium chloride and hydrogen. Or, I could react sodium carbonate and hydrochloric acid. And that'll get that same salt I'll produce, sodium chloride, and water, and carbon dioxide. Or, I could use the reactants, sodium oxide and hydrochloric acid, and I'll produce sodium chloride and water. Or I could react sodium hydroxide and hydrochloric acid, to form sodium chloride and water. So, there's four different ways there that I can produce the same salt. There's different combinations of reactants that will all give me sodium chloride. Okay, time for a quick check. Can you complete this general equation? Metal oxide plus acid forms salt plus, say the answer. Great work! It's water. Can you complete this general equation? Metal plus acid forms salt plus, what's the other product? Super! It's hydrogen. Okay, how about this one? Alkali plus acid forms salt plus... Well done! Water! Metal carbonate plus acid forms salt, water, and what's the other product? It's carbon dioxide, that's correct! So, time for some independent practise now. I've got two questions here for you, and I'd like you to write the answers down. What you need to do is use those four general equations that we just looked at, to list all the possible ways that you could make potassium sulphate, and then do the same again for copper sulphate. So, what are all the different combinations of reactants that you could use to make those two salts? Make sure that you write the full equation down, and you'll need to pause the lesson here, and resume once you've written your answers. Off you go. Okay, let's go through the answers then. These are the four combinations of reactants that you could have used to form potassium sulphate. I'd like you to pause the lesson here, so you can mark your answers, and correct any that you didn't quite get right. Great effort! And here are the four combinations of reactants that could use to form copper sulphate. So, again, I'd like you to please pause the lesson now, and mark your answers. Keep up the hard work. Planning the experiment. So, there are lots of different circumstances that might impact which combination of reactants we want to use in order to produce a particular salt. So, we've just seen that there are lots of different combinations of reactants that you could use to produce the same salt. And depending on our circumstances, we might need to choose one of those particular reactions, or there might be one that we particularly don't want to use. And here are some of the reasons that our circumstances might change. There might be a particular reaction that we want to study. If that's the case, we'll most likely choose to use that combination of reactants. It might depend on the availability of the reactants. So, for example, if we haven't got very many of a particular reactant in our laboratory at school, we might not want to use those reactants, just in case we don't have enough. It could depend on the waste products. We might not want to produce a reaction that's going to form lots of waste products. Or it could be down to the ease of seeing a reactant in excess. What we mean by this, is the fact that when you're making a salt, you need to add one of the reactants to excess, so that there's too much of it eventually, so we know that the reaction has fully completed. So, if it's a lot easier to see that one particular reactant's been added to excess, we might want to choose that combination of reactants. So, if we want to make the salt copper sulphate, I've given you some of our circumstances. So, imagine the circumstances for us performing this practical. And I'd like you to select which reactants you're going to use, and explain why you've chosen them. So, have a read of our circumstances, and then decide which reactants you're going to use to make the salt, copper sulphate, and why. So, can you pause the lesson here please, and write your answer down, and then resume when you're ready to move on with the lesson. Okay, so this is the combination of reactants that I'm hoping you picked, based on our circumstances. We're going to use copper oxide, plus sulfuric acid to form copper sulphate, and we'll also produce water. This is because using copper will take too long, we will produce too many waste products using copper carbonate, and our lab may not have enough copper hydroxide for the reaction. So that's why we've picked copper oxide and sulfuric acid. Really well done. I'm going to go through with you now, the steps of the reaction that's done in order to make a salt. So, I'm going to go through each step of the process that would be performed. So this here is step one, you can see in the picture. For this step, we need a beaker, our sulfuric acid, a tripod, and a bunsen burner for heat. And all that we're doing in this step of the practical is first of all, measuring out our sulfuric acid, adding that into the beaker, and then gently heating the acid. You don't want the acid to get too hot, because it will boil, and it will start to spit out the top, which can be dangerous. So that's what step one involves, gently heating the acid, so that it's nice and warm, ready for step two. This is step two then. For this step, we're going to need a glass rod for stirring, a beaker; that's the same beaker that we used in step one, the sulfuric acid that we warmed in step one, copper oxide; that's our second reactant, a tripod, and we've still got our bunsen burner. Now what we're doing in this step, is we're adding in our second reactant, the copper oxide, into the warm sulfuric acid, to cause the reaction to take place. The fact that the sulfuric acid is warm, will speed the reaction up. And then we can also use the glass rod to stir the reactants together to help increase the speed of the reaction. We're going to continue adding spatulas of copper oxide until excess copper oxide can be seen on the bottom of the beaker. So when we've essentially added too much copper oxide, so that it can't react with any more sulfuric acid, we've used all the sulfuric acid up, we can call it an excess. And so some of the copper oxide remain un-reacted, and just sit on the bottom of the beaker. So the reason that we do that is just to ensure that all of the sulfuric acid has completely reacted. So, once we've added our copper oxide to excess, we know the reaction has completed, and we've now got our salt and our water that has been made. So, step three. For this step, we need to perform filtration. So, for filtration we need: a funnel, some filter paper, that's the excess copper oxide that we're going to filter out, a beaker, a new beaker. That's our second beaker so far. And then we've got through there, the products that we've produced in step two. Copper sulphate, that's the salt, and water. So, what we're doing in this step is taking the products from step two, and we're pouring that beaker of products into the filter paper. And the filter paper's going to catch the excess copper oxide. The excess copper oxide is insoluble; it can't dissolve. So it's going to get caught in the filter paper, and then the copper sulphate and the water are going to be able to pass through. The reason that the copper sulphate can pass through, the salt, is because the salt's dissolved in the water. So, it will go through the filter paper with the water, because it's dissolved in it. So, we can filter out any excess copper oxide, and then in the bottom of our beaker, we'll be left with copper sulphate and water, the two products that we've just made. Step four. For this step, we need an evaporating basin, our products, copper sulphate and water, a tripod, and the bunsen burner. So this step is called crystallisation. And what we're doing is taking our products that we just filtered in step three, and we've poured them into an evaporating basin, which is essentially a ceramic bowl which can withstand really high temperatures without melting. So there's no chance of our bowl melting during this part of the process. So we pour our products in, and then we start to heat. And as we do that, the water in the products will eventually start to boil and evaporate. And as the water evaporates, we will gradually be left with crystals of our salt. So, the salt crystals will get left behind in the basin, and the water will evaporate. It's really important now that we only do this until there's about one centimetre of water left. If we go any lower than that, it will start to spit out of the top of the basin, which can we dangerous to get hot chemicals on your skin. So it's really important that we only evaporate off the water until we've got about one centimetre of water left. And then we move onto step five. For this step we need: some sunlight, the same evaporating basin, you want to wait for it to cool down so that you can move it, and our last remaining bit of water, and the copper sulphate. So once your evaporating basin cooled down from step four, you can move it onto a windowsill. And you're going to leave it there in the sunlight for about 24 hours, for that last bit of water to evaporate, and when that happens, you'll be left with pure copper sulphate crystals in the bottom of your evaporating basin. So that's how we can make copper sulphate. Create a list of equipment you will need to complete this practical. So, to remind you of the steps of the practical, and what equipment we were using, I've put the pictures that we've just looked at together on the screen for you. And what I'd like you to do now, is write a list of all of the pieces of equipment that we'd need to complete this practical. So, can you please pause the video, and write the equipment list, and then resume the video when you're ready to go through the answers together. Okay, let's go through the answers! So, to complete this practical, you'll need: two beakers, a tripod, a bunsen burner, a glass rod, funnel, filter paper, an evaporating basin, and then I've also put two extras down which you may not have got from the pictures, but you would need them anyway. You need a measuring cylinder right at the start to measure your volume of sulfuric acid. You'd also need spatula to put the copper oxide into the acid. So I've put those separately because they weren't on the pictures, but if you pick those up as well, really well done! Add any bits of equipment that you missed to your list, and then let's move on! Writing a method. So, now I'm going to talk you through the steps needed in order to write a really great practical method. And then you're going to have a go at applying this new knowledge, and writing a practical method for the "Making a Salt" practical that we just went through together. This here is the rules needed to write a really great practical method. If you use that formula for each step of your practical method, the method that you write will be really great. So we're going to have a look at how to put this into place together. You need to start off with an imperative, which is a command word. So, something like "place" or "put" or "measure" or "record." Then you need to follow that with a quantity, so you need to be really nice and specific. Have you got 300 millilitres? Or do you need to measure 30 centimetres? Or are you taking 2 pieces? Be specific. And then finally, you need to specify what equipment you're using in order to do that step of the method. Is it a measuring cylinder, or a beaker, or a bunsen burner? What's the equipment that you're using? So in order to show you how we can use this formula, in order to write a really great practical, we're going to go through an example together. And that example, is how to make the perfect cup of tea. So, if I'm using that formula, my first method step for creating a perfect cup of tea would look like this. Measure 300 ml of water using a measuring jug. I've started off with an imperative, a command word, "measure." Then I've been specific and given the quantity of water, 300 ml. And I finish off by saying what equipment I'm using in order to do that step. So it could be a measuring jug if we're at home, or that would be a measuring cylinder, if we're in a lab at school. The next step would look like this, if I'm using the formula. Pour the 300 ml of water into a kettle and turn on. Again, I've started with my imperative. I've included a quantity, I've been really specific. And then I finished off by specifying the equipment, in this case, a kettle. And the next step would look like this. Place one teabag in a mug. I'm being really direct and specific with what I'm doing. There's no room for interpretation. And this is what makes a really good practical method. So, it's time for you to have go, now. I've put that formula up at the top for you: the imperative, quantity, and equipment, just to remind you what you need to include in each step of your practical method. And I'd like you to help me improve a method for making a sandwich. So I've got some parts of a poorly written method that are going to go up on the screen. And what I'd like you to do, is improve each method step and make sure it follows the rules, follows the formula, for writing a great method. So here's the first one for you. This is the poorly written method step. You need to first of all collect some bread. Now, what I'd like you to do, is improve that method step so that it follows the rules, follows the formula. So, can you please pause the lesson, and have a go at rewriting that method step, and resume when you're ready to move on. Okay, let's go through the answer then. An improved version of that method step would be this. You could've written it slightly differently, but along these lines. You need to make sure you started off with an imperative, so I've gone for "collect." Two slices, that's my quantity. Of bread, that's my equipment, that's what I need to do it. So, collect two slices of bread. Give yourself a tick if you wrote one similar to that. Okay, now have a go at improving this method step. Next, you will need to find some butter, which you spread on the bread. So that's written poorly, and I want you to turn that into a well-written method step, using the formula at the top. Pause the lesson and write your answer, and resume when you're ready for the answer. And there's the answer! Again, yours could be slightly different to this, but make sure it follows the rule. Does it start with an imperative? So, I've gone for "spread." Five grammes, that's my quantity of butter, on the bread using a knife, that's my equipment. Okay, great work! We've got one more to do together. There's the poorly written method step. You should then cut up some cheese. Now I'd like you to improve that method step please, so pause the lesson and write your answer, and then resume when you're ready. Okay, hopefully you came up with something like this. Cut three slices of cheese using a chopping board and sharp knife. Really great work, well done! So what I'd like you to do now is write a method for making copper sulphate. Use the pictures to help you. You're going to use the knowledge you've just learned about how to write a really great method. I've put the formula up at the top of the slide for you, so that you can just be reminded of it. And I'd like you to turn that method for making copper sulphate, into a really well written practical. Use the pictures to help you, but just a warning, you'll need to write more than one step per picture. So, can you pause the lesson please, and give this task a go, and resume when you're ready for the answers. Okay, so I'm going to go through the answer with you now. Of course your written practical may not be exactly the same as the one I'm about to show you, the one that I've written, but as long as it follows the same lines, and you've used those rules of using an imperative, a quantity, and the equipment, that's a great job. Okay, so let's go through the answer. Before I bring up the answer onto the screen, I just want to say that your method may not be identical to mine, but as long as it follows the gist of the practical method, and you're using imperatives, quantities and the equipment that's absolutely fantastic. So I'm going to bring up my answer now, and I'd like you to compare your written answer to mine. So, here's the first half of the practical. Okay, if you need any more time you can pause the lesson to compare your answers, and then resume when you're ready to move onto the next half of the practical method. And that's the end of the method. Again, pause the lesson here if you need to have a go at marking the second half of your lesson if you need a bit of extra time. Well done for putting in so much effort, there, that was a great job. And hopefully now you can continue to use those rules about method writing for other practical methods in the future, too. And that's the end of the lesson! Well done, fantastic effort that you've put in once again. In this lesson, we've looked at all the different ways you can make a salt. We had to look at a method for making a salt. And then you even had a go at writing a practical method for performing that practical. So, really well done! Next lesson, we're going to be having a look at the difference between a hazard and a risk, and how we can minimise hazards and risks in practicals. Don't forget to complete the exit quiz once this video ends, just click onto the next slide and it will be there waiting for you. See you next time!

Which of these general equations is correct?

Which of these equations is correct?

Which formula do we use for writing a great method?

Which of these method steps is the best written?

Revision - how can we test for the presence of carbon dioxide?

Revision - how many atoms are there in Al₂(SO₄)₃ ?

Method Writing

Describe potential chemical combinations that could be used to make a particular salt

Choose appropriate chemicals and equipment to prepare a given salt

This lesson investigates potential chemical combinations that could be used to make a particular salt, looks at how to write the perfect method and then applies this knowledge to the practical "making a salt".

Science

Y9 Science

Key Stage 3

Year 9

Miss

Method writing

Reactivity

Chemistry

THEME

UNIT

Electron configuration

Ions

Chemical formulae

Symbol equations

Acids and metals

Acids and metal oxides

Making a salt

Acids and metal carbonates

Hazard and risk

Reactivity series

Metal ores

Displacement

Alloys

Producing a voltage (Part 1)

Producing a voltage (Part 2)

Harry Brearley

Review (Part 1)

Review (Part 2)

What does the atomic number of an element tell us?

How can we work out the number of neutrons in an atom?

What does the group number of an element tell us?

What is the maximum number of electrons that can fit in the first electron shell (shell 1)?

What is the maximum number of electrons that can fit in the second electron shell (shell 2)?

Which group of elements on the periodic table are not reactive?

If an atom gains an electron, what charge ion will it form?

What is the correct definition for an ion?

Revision - a magnesium atom contains 12 electrons. What is its electron configuration?

Revision - what is the electron configuration for nitrogen (which contains 7 electrons).

Revision - what does filtration separate from a liquid?

How many elements are there in HNO₃?

How many atoms are there in HNO₃?

Oxygen is in group 6 of the periodic table. What charge ion will it form?

A compound contains 1 magnesium atom and 2 chlorine atoms. What is the chemical formaulae of the compound.?

What is the relative formula mass of CH₄? (The relative mass of carbon is 12 and the relative mass of hydrogen is 1).

What is the correct general equation for a metal reacting with an acid?

What type of splint do you need to use when testing for hydrogen gas?

What pH is an alkali?

Zinc oxide + nitric acid -->

Revision - if an atom gains 2 electrons, what charge ion will it form?

Revision - sodium contains 11 electrons. What is the written electron configuration for sodium?

Lesson overview:Method writing

Reactivity: