 In a previous video, we have seen that acids react with bases to give us salt and water. And based on this, we also said that if something is reacting with an acid and giving us salt and water, then that something has to be a base. And similarly, if something is reacting with a base to give us salt and water, then that something has to be an acid. Now we are going to use this same property to study how acids and bases react with oxides of metals and non-metals. And this will tell you a lot of surprising things about metals and non-metals. So let's begin. Let's begin with an example. Here I have magnesium oxide. Magnesium is a metal and I am taking its oxide. So I am reacting a metallic oxide with an acid, HCl. Now can you pause the video and try to guess what the products are going to be formed? And based on the chemical reaction, can you also guess what is the nature of magnesium oxide? Pause the video and give it a try. Now if you have tried it, let's see. So now magnesium iron is going to be attracted to chlorine minus iron. And finally we will get magnesium chloride. Its formula is MgCl2. And similarly, hydrogen will be attracted to oxygen and we will get water H2O. Let me quickly balance this equation. Here we have two hydrogen and two chlorine. So here I'll write two. Okay. So here this compound is reacting with an acid to give me a salt and water. And we have seen earlier that only acids and bases they will react to give us salt and water. So this tells us that this compound has to be a base, right? So yes, magnesium oxide or metallic oxide, they generally are basic in nature. Metal oxides, they will behave as bases. They will react with acids to give us salt and water. Now let's look at one more example to be sure. So here I'm taking calcium oxide. Calcium is a metal and I'm taking a metallic oxide. And I'm reacting this with an acid HCl. So in this case also, calcium will now get attracted to chlorine iron. And finally we'll get calcium chloride. The formula is CaCl2. This is a salt. And now hydrogen will get attracted to oxygen and we will get water H2O. So here also you can see that metal oxide is reacting with an acid to give us a salt and water. So from this we can conclude that metal oxides, they are basic in nature. They behave as bases. They react with acids to give us salt and water. Now some of you might have a question. That now we know that bases are compounds, which when mixed in water or any aqua solution, they increase the amount of OH- ions. How is it that calcium oxide, this when mixed in water, this will increase the OH- ion? How is it a base? So that is a very good question. For this, let's look at little bit in depth. So here I'm taking calcium oxide and I'm mixing it with water. Now what's going to happen is that calcium oxide, this will dissociate and break into its ion. Calcium plus 2-ion and oxygen minus 2-ion. And this oxygen ion will combine with water molecule. And they both will form hydroxide ion, OH- ion. Well since there are two oxygens and two hydrogens, to be correct I should write 2OH-. Okay now you can see that when a metal oxide is mixed in water or any aqua solution, it will give rise to hydroxide ion. And since it is increasing the amount of hydroxide ion, we can say that metal oxides are also basic in nature. In fact, to prove the same I have an experiment for you. Here I have calcium oxide mixed in water. And I am putting a red litmus into it. You can see that the color changes to blue. And you know that that only happens in case of a base. The red litmus changes to blue. So hope this convinces you that metal oxides are basic in nature. Okay now with this, can you guess what will be the products formed when a metal oxide reacts with a base? For example, let's take calcium oxide and let's react it with sodium hydroxide. Can you guess what will be the products formed over here? Well, here there will be no reaction happening. In fact see, calcium oxide, we have seen that this will break down to give me calcium ion and hydroxide ion. Similarly, sodium hydroxide. This will break down to give me sodium ion and hydroxide ion. Something like this, right? Now what reaction can happen and what new products will be formed? Even if there is double displacement reaction happening, sodium will come here and get attracted to OH-ion and form again any OH, right? So these ions will exist in the solution and no new products are going to be formed. And that's why we can say that metal oxides, they are not going to react with bases in general. So here we can say that metal oxides, since they react with acid to form salt and water, that's why they are basic in nature. And metal oxides, they do not react with bases, generally speaking, because there are some exceptions. For example, aluminium oxide or zinc oxide or some other oxides of metal. They will react with acid to form salt and water, but they will also react with bases to form salt and water. So they are both acidic and both basic, right? But let's not worry about them right now. Right now we can say that, generally speaking, metal oxides are basic because they react with acids to form salt and water. Now let's talk about non-metallic oxides. So here I have carbon dioxide. See, carbon is a non-metal and I have taken its oxide. So I'm going to react this non-metallic oxide with a base, sodium hydroxide. So in this case, sodium will react with carbon dioxide and form sodium carbonate. The formula of that is Na2CO3. And along with this, we will get water, H2O. Okay, let's balance this equation. So two over here and yes, this is balanced. Okay, so here we can see that this compound is reacting with a base to give me salt and water. And we have seen earlier that acids and bases react to give salt and water. So by that I can say that this compound has to be an acid. Then only it can react with a base to give me salt and water, right? So yes, non-metallic oxides, they are acidic in nature. They behave as acids. They will react with bases to give us salt and water. So from here we can conclude that non-metal oxides, they are acidic in nature. And now you might be wondering, how is this happening? Because I know that by definition, acids are those compounds which are when mixed with water or any aqua solution, they increase the amount of H plus ion. So how is carbon dioxide increasing the amount of H plus ion? So for this, let's look at a little bit in detail. So see, when carbon dioxide is mixed with water, it will form carbonic acid, H2CO3. And you know, this generally exists as H plus and HCO3 minus ion. So you can see that when carbon dioxide is mixed with water, we are getting more number of H plus ion, right? The amount of H plus is increasing. And that's how we can confidently say that carbon dioxide, this non-metallic oxide, is acidic in nature. Now let's summarize the video. After watching this video, you would be able to answer, what is the nature of metallic oxides and what is the nature of non-metallic oxides? And don't worry if you are still confused. You can go back and watch the video again.