Chemical properties are characteristics of a substance that is observed during a reaction in which the chemical identity of the substance is changed. Here we discuss about the Chemical properties of Metals and non-metals in this video which will give a complete understanding of the concept.
Few important chemical properties of matter are mentioned:
- Enthalpy of formation
- The heat of combustion
- Coordination number
- The degree of ionization
Let us also look at this table to have an overlook at the differences between Metals and Non-metals.
Metals are solids in room temperature except for that of mercury
The non-metals exist in all three states
Except for sodium, these metals are very hard
Except for diamond, these non-metals are soft
Metals are ductile and malleable
Non-metals are brittle and could be broken down into pieces
Metals are shiny
Non-metals are non-lustrous except for iodine
Metals are electropositive in nature
Non-Metals are Electronegative in nature
These metals have high densities
Non-metals have low densities.
As we have seen the differences of metals and non-metals, let us look at few more properties of these chemicals.
Metals react with oxygen, they burn in oxygen to be able to give you a metal oxide, which is usually basic but can also be amphoteric and that means that it shows both basic and acidic properties. The chemical properties of these metals are that they are easily corrodible and can close electrons. Metals can also form basic oxides and also acts as a very good reducing agent.
Non-metals are very few. These non-metals include carbon, hydrogen, phosphorus, nitrogen, sulfur, oxygen, all halogens, selenium and the noble gases. These non-metals are present in the right side of the periodic table. The Chemical properties of non-metals are that they generally contain 4-8 electrons in the outer shell. Nonmetals are readily lose or gain valence electrons and they also form acidic oxides. It should be noted that non-metals are great oxidizing agents.
Both metals and nonmetals take different forms which have different shapes and properties when compared to each other.
So what we have seen up till here is that metals react with oxygen, they burn in oxygen to be able to give you a metal oxide, which is usually basic but can also be amphoteric and that means that it shows both basic and acidic properties. So we are here. But do all metals react with oxygen with the same reactivity? Do they all show the same kind of reactivity? Or do they behave differently? One of our primary goals in this chapter is to understand how reactive each metal is. In other words from our previous understanding, how willing is it to give out its electrons? Because like we saw, metals react by giving electrons, right?
So we are trying to see how willing they are to give their electrons. For example, if you take the alkali metals like sodium and potassium, they react vigorously. You take them out there, even room temperature is enough for them to begin to start reacting with oxygen and lose their electron – that vigorous. So you keep them out there, no heat nothing is required, even room temperature is enough. Now we begin there and then metals like magnesium, aluminum, zinc and lead, they burn, they react with oxygen to be able to give you a thin protective layer so that after that layer is formed it protects the inner part from being oxidized. And now iron does not react with oxygen, does not burn in oxygen but iron filings burn vigorously. And if you look at copper, copper doesn’t burn but has a black copper oxide that forms over it. And now in the end of the spectrum you have gold and silver which do not react with oxygen even at very, very high temperatures.
So, we can begin to observe that even amongst metals, so we first classified things into metals and non-metals, and even amongst metals you see something, something of a pattern. Right? Somethings are reacting so vigorously, losing their electrons so easily and somethings are not. And we have already seen some basis to this right? We have seen why this is happening a little bit. And the question that you will have in your mind right now is what’s so special about gold and silver? Why don’t they react even at such a high temperature? So we want you to keep that question along with you as we proceed. And now the idea here is that different metals have different reactivities. Metals react with oxygen to form oxides.
We’ve mostly basic oxides, some of them are amphoteric oxides, and gold and silver, there is a huge spectrum of reactivity. Different metals react with, at different rates to oxygen and something beginning at calcium, sodium and potassium at this end of the spectrum to gold and silver at the other end. And we’ll see little bit more about this as we proceed with our next line of thought which is what two metals do if you play with them in water. So before you set about learning something it’s very interesting. I used to have a teacher who used to walk in first class of the year, just look around and then ask a very interesting question, “Hey students, who got first rank last year?” and I used to like okay, how does it matter?
It was fascinating to me as to people believed in this. I didn’t understand this. It was like the teacher used to step into the class and go like you know “Okay, my job is to figure out the good eggs from the bad eggs.” Now as if that’s their job to classify the students into good, bad, mediocre and you know, not at all good or something like that. So today I am going to become my sir who asked me good student, bad student, average student and so on and so forth. So our job today is to classify these metals into good, average, bad and, you know, failures. So let’s begin doing that. So what is the tests for them right? Every, every, in order to figure out who is good and bad, we need a test, we need an exam. In this case the exam is, what we are going to do is take the, take these metals and find out who is going to react with water. So our classification is the one who reacts really well with water. Great student. Right? Oh but wait. You reacted very well with cold water itself, awesome.
But, but, but if you did not really do that, if you failed, then we go to warm water, right? if you failed that as well we go to steam. So why are we doing this? What’s cold water, warm water and hot steam and all that to do with this? So we find that what we’re trying to do is you take a metal and you’re trying to play with its reactivity right? How reactive it is. That’s what we have been doing in the previous module as well. So our job here is to make it so that when you take a metal and try and react it with cold water, if it does not react, our job is to make it so that we increase the temperature, the probability of collisions and the force with which these collisions happen is going to become more. Kinetic energy is much more. And that’s temperature right? Temperature is just the kinetic energy. So these become more, probability of collision becomes more. So if cold water doesn’t react, try with hot water. That also not possible, increase temperature even more. But at that temperature water won’t exist in its liquid state. It will become steam. And you decrease the volume of this steam, you might even be able to make it so that more and more collisions begin to happen and then let’s see if they react there. If none of these happen we are back to our old teacher who says, “They are failures my friend. You can’t do anything with them”. So I started to believe in this illusion and start playing with it. So let’s start and let’s take our water.
We have cold water with us. Level 1 test. And let’s begin to start putting and playing with each of these metals. What do we find? Sodium and potassium, woah, vigorous reactions with cold water itself. Yeah you’ll watch it as sodium and potassium begins to start flowing around, sodium begins to start running around the place, catches fire. Potassium catches fire immediately, much more than even sodium. Starts running around in the water. Okay. So what have seen here? Mathematically how will you show this? Or as a reaction how will you show this is, sodium and potassium, right along with water give you sodium hydroxide and potassium hydroxide respectively and hydrogen gas.
But the hydrogen gas, its reaction is so vigorous that the hydrogen gas catches fire immediately. It’s that vigorous. Woah, these guys deserve to be first rank. So we will take them up and keep them there. They are way up there, sodium and, potassium and sodium in that order. And then let’s see what happens with calcium. Calcium doesn’t react that vigorously. So we take calcium, put it in cold water, great. Reacts little slower. Same reaction calcium plus water gives you calcium hydroxide plus hydrogen gas. Now in this case the hydrogen gas doesn’t burn immediately because the reaction is not so vigorous, so what happens is that the hydrogen gas begins to form bubbles on this little piece of calcium and calcium floats up because hydrogen is lighter. Woah. That must be an interesting thing.
You place the calcium inside it begins to start floating upwards. So it reacts with cold water, great. Take it up there, rank 3. So it’s important. Then what you begin to do is you begin to start wondering. Take all the other metals, none of them seem to care. They’ve all failed this exam. Which exam? The cold water, CW exam. So then next exam is the HW exam, you take the HW exam. Yeah, and then what happens? So already 3 people have passed, you try the next one. Magnesium does not fail in cold water but it was lucky enough, 2nd attempt the H water, we put it inside, it begins to react and with warm water, because there are more collisions now it’s warm water the temperature is enough to start pushing it to let go of its electrons.
So when magnesium let’s go of its electrons in hot water, this is the reaction that you get. Magnesium plus water giving you magnesium hydroxide plus hydrogen gas. So you begin to see the pattern here. Metals react with water, when they react, they form a hydroxide, the metal hydroxide and hydrogen gas. Now in this case as well hydrogen gas bubbles onto the magnesium and magnesium floats up. Interesting right? No but the sad thing is the other metals fail this test as well. What are these metals going to do in life? Let’s begin to start seeing, let’s, let’s raise it up one level so we have the steam test now. So CW and HW are over. The steam test and then you find finally that metals like aluminum begin to start reacting with steam. So you take aluminum with water, it begins to form aluminum hydroxide and hydrogen gas. So you proceed this way. You take this one and start ranking it up, because magnesium is already there, yeah, with a hot water test. So you have the cold water guys, the hot water guy, and now the aluminum which is steam and iron as well.
So as we can see, iron reacts with steam to form oxide, its oxide and hydrogen gas. So but, we have our rankers, the second ones and the third ones our so called belief in good students, average students and mediocre ones. Right? Or rather the poor students. And then, but what do we have here? Like every class, right, we all need to have failures. So over here we have lead, we have copper, we have gold and silver. They don’t react with water. They’ve failed the water reaction test. And therefore they go down that list. And as you can see we have built a progression here from the most reactive to the least reactive metals. We have grouped them that they react with cold water, warm water or hot water, steam and no matter what you do they don’t react. So we are gently beginning to understand that amongst metals, there seems to be a series of people who are willing to lose electrons very easily to people who are not willing to do that. And let’s see if we can force some of.
So we have taken metals and played with air. We’ve seen what happens when we play with them with water and now we know that some are poor failure students right? They refuse to react with either of these. So then what do we do now? We brought the big boys in. Right? The acids. Acids can force any, many, many compounds to react. Now, as we can see all our metals are lined up in their rank order, right? Yeah, the most reactive at the top and the reactivity is going down. Now what we will do is, what do we need now? An acid. Let’s choose hydrochloric acid. We have our hydrochloric acid over here and let’s first try with – let’s look at potassium and sodium and realize that what happened when they reacted with cold water?
It was a vigorous reaction, right? Now imagine potassium and sodium reacting with hydrochloric acid. Now it’s going to be almost explosive. It’s going to be an explosive reaction and the hydrogen that is released is going to burn and get oxidized into water. It’s that amount of temperature we’re talking. So in other words what we are trying to tell you is – don’t do that! Never take potassium or sodium into this experiment, it’s going to be too reactive, in other words it’s going to be explosive. So let’s go down a little bit and let’s pick our magnesium. Right, so let’s take magnesium out and push it down and let’s have it and see what happens when magnesium reacts with hydrochloric acid, dilute hydrochloric acid.
And what you observe is that magnesium forms its chloride as you can see. So magnesium and dilute hydrochloric acid form their chloride and releases hydrogen gas. Simple enough reaction. So you can test this out, like you might already know this, for the ones who already know, you know that hydrogen gas is released you can test that by holding it for a while, not too hard, just don’t get too much pressure there. So hold it for a while and then when you open it and take a matchstick, you get a pop sound. And then you know that it’s hydrogen. So you have magnesium, great. Now let’s forget that. And let’s bring our next element here, which is aluminum. So you bring the aluminum and push it down and when it goes inside the hydrochloric acid and they react, what do you get?
Aluminum also reacts with hydrochloric acid and it gives you, exactly, aluminum chloride and hydrogen gas. Now what we need you to observe is in each of these cases watch the rate at which the bubbles are coming up. That tells you the rate at which this reaction is happening. Let’s also try iron. So you take iron with you and then you see what’s going to happen? Iron reacts as well. So in which of these is the bubbling. Observe it.
That’s right, in the case of magnesium. So magnesium reacts fastest and then aluminum and then iron. So our ranking seem to be making a little bit of sense right now. Right? And now what we want you to observe is that copper, let’s pick it up and see what happens. So we push it down. Copper doesn’t want to seem to react with this. So this guy is failing him in this test. Something has to be done. So now let’s go back and let’s try and play with another guy. Another big boy and see how that’s going to create a situation. So let’s take our hydrochloric acid, send it back wherever it came from.
And what we are looking for right now is, aah, that’s right, nitric acid. So we take nitric acid and you begin to start reacting these metals with it. What you begin to get is that hydrogen gas is not released, although the same reaction occurs. Yeah. It does react with the acid but does hydrogen gas is not released because nitric acid is a very good oxidizing agent. So what it does, it oxidizes hydrogen and eventually what you get is nitrous oxide, just NO or N2O or NO2. So of these you might be particularly interested in nitrous oxide. It’s also called a laughing gas. So we go to a dentist sometimes they might give it to you.
It’s a chance for you to laugh for no reason at all. So what we want you to do is now that you’ve observed this. Even though this is the case, just 2 metals over here, manganese and magnesium do release hydrogen and you might want to think that is the case. Now that we’ve played with nitric acid as well let’s take it and set it aside.
And now we’re going to look at our complete failures, right? The ones, gold and platinum. These guys don’t react with anybody. Yeah, so we need to find someone that’s a really, really big guy, who is going to force them to give their electrons out. So in our list, let’s look at someone. Aah, there he is. Aqua regia. It’s another word for water, royal water. Now why this is called this is because it’s kind of a mixture. As you can see it’s a fuming liquid so let’s bring it very carefully. Yeah. So this fuming liquid is one of the most corrosive substances in the world. It is a mixture of 3 parts of hydrochloric acid and 1 part of nitric acid, both concentrate.
The funny thing is this can do something that neither of them can do alone. Now isn’t that interesting. So this substance here, aqua regia, is one of the very, very, very few substances that can actually dissolve gold and platinum. So we are to take this. That’s right. Finally somebody is there who can make gold react. Now you’re riding theme of the question which is, why is there a difference between all these reactivity? Yeah. We’re going to try and address that in a few moments and you already have an idea about that, don’t you? Because it’s the ease at which these are willing to lose electrons. Right?
How do metals react? By giving out electrons, right? So, the ease at which they do this is affected by, like we discussed, the ionization energy, right? How easy it is to kick them out. So this is just a way for us to remember this even more. So as you can see, when you take it to the extreme, you can even make gold and platinum give out their electrons and dissolve.
So with this done we’re going to try and play with one next thing, which is, what happens when these metals react with salt of somebody else amongst them. So when one metal reacts with a salt of another metal, what’s going to happen? So that’s going to be our focus in the next one. So now that you realize this, we’ve seen what happens when metals react with water and when metals react with acids. So we see the pattern here from your previous chapter. You know that the chapter was acids, bases and salts, right?
So you know there is a pH scale where the pH can be at 7. So we have seen what metals do at this range 7, which is water. And we’ve also seen what happens in the scale below 7 which is acids, right, which are acids. And then we start going towards the scale that is beyond 7. Why didn’t we talk about that? Yeah. Bases. How do metals react with bases? Now the interesting thing here is metals react by giving electrons right? Now bases also want to give electrons. So it’s not really a relationship there. There is no give and take. So it’s going to be really unlikely that this happens, right? And that’s exactly what you’re expecting.
And that’s what happens. Any strong base which is very likely to give out an electron, there are no reactions. Except for really, really weak bases where metals force their electrons out there. So now that you have the entire pH scale with you it’s time to get into what we really wanted to do which is the reaction of metals with other salts of metals, and let’s see what happens over there. Now we told you this. The question that’s been running through your mind is why are we doing all this? Right? And you already know that we told you right? When the teacher enters the class they always try to do this. They want to classify the student’s right? Into good ones, average ones, poor ones and the failures. And we told you that’s exactly what we are trying to do here right? Amongst the metals. We are trying to create some competition amongst the metals. So we did this. You saw that we took the metals reacted, had them react with oxygen and some of them reacted but so many of them did not. So how do we rank those? Then we went into water and some more reacted and then we could rank a few more. And then to make a lot more of them react, we went to our acids right? Made most of them react. But then some of them are still not budging.
So how do we rank some of them? So there we hit upon an amazing idea which says this. When one metal reacts with a salt of another metal, right? So we take a metal and then take a metal salt in its aqua solution or in a molten state, right? So we take a metal salt, either take a salt solution in water or heat it so much that it becomes molten. Then what is going to happen when these two are put in the same environment? So you have a metal and you have a salt of another metal. Now what we know here is if the metal that’s there is higher, is of more reactivity, it’s higher in the rank that we have, it’s going to kick this out and occupy its position. Then what do you, what do you, what hits you right? If you were Sherlock Holmes, you would know that, okay, here is a chance for me to be able to figure out all the rankings correctly. All you have to do is take a metal salt, make it react to the metal. If there is a kicking out happening metal is more reactive. If nothing happens there is no reaction.
Now we want to make this more relative, let’s do this right? Let’s go back to our lab and now as you can see right? Let’s bring in what we already had. Set a couple of test tubes over here and in one of them let’s add copper sulphate solution. And in the other let’s add ferrous sulphate solution. So one is a salt of copper and the other is a salt of iron. So contenders for our competition are who? Copper and iron right? So we have these two competing for who is more reactive. You might already know who is more from our previous experiences because copper kind of did not react with many substances.
So you might know this but let’s really test this out. So we have copper sulphate and ferrous sulphate. You dip an iron rod here and a copper piece of wire over here. So what are you supplying for them? The metal itself. The metal is reacting with a metal salt and a metal is reacting with a metal salt. You keep this apparatus over here and let it be for a while, and as you can see, what begins to happen is that the solution over here, the copper sulphate solution is beginning to turn its color. Okay something is beginning to happen. And the iron nail is looking pretty ugly right now. Something is coated onto it pretty randomly.
So slowly this solution is turning mild or slight green, can you see that? So what you first thing you observe, a reaction’s happening over here. That itself is enough for you to infer that the metal is more reactive than the salt, whichever metal salt was which is copper. So iron kicked copper out. In other words iron won. Iron must be higher on that list. Now we going to slowly build our list in this way and what happens in the other test tube? As we expect, nothing. Right? Copper isn’t able to kick iron out. Yeah.
So iron is stronger. So with this, let’s pull this back and let’s really begin to talk about this in generic way and what you observe is that when you take a metal A that is more reactive and make it react with a salt of metal B, that’s lower in that order. So metal A is higher and metal B is lower, then metal A kicks metal B out and forms a salt that metal B once was and then releases the less reactive metal. So that’s why in the case of the iron nail inside the copper sulphate solution you could see that copper was getting deposited around the nail, which means that you are getting copper outside from its solution.
So with all this in mind the fact that now you have the displacement reactions, these are called displacement reactions, one kicking another one out. Displacement like you learnt in your first chapter. You can begin to rank these in a way that you can see now. Let’s bring this here right now and let’s really talk about this because this is what we have been working for. This called the reactivity series. Now what you see here is the react, all these metals arranged in their order of reactivity. So we know from our beginning itself right? We took, even you take it out and keep it in the air, it starts to explode, it starts to burn, potassium, way up there. And right down to where you can see platinum.
This pattern has been maintained right? So potassium and sodium and calcium and so on and so forth. Magnesium, aluminum finding themselves in the middle. Copper finding themselves below. Iron somewhere in the middle. So if you see this entire series whatever you’ve seen till now is being reconfirmed by what you’re seeing over here. Now, now that you already know how all of this works at the atomic level what do you know? This basically a statement about how easily each of these metals lose their electrons right? So this loses electrons very easily, potassium, and way down to platinum where it’s very difficult to make it lose it. And where does all this come from?
It’s from the amount of energy required to kick an electron out of these metals. So with this completely in place now let’s jump into very, very interesting concept which is, till now we saw how metals react with many reagents. Right? Let’s see what metals do when you bring them together with non-metals. So metals that want to give electrons meeting things that want to take electrons. That should be an interesting combination. Let’s see what happens.