Description: The article focuses on the topic about activity series. We can comprehend something more about activity series in chemistry with the experiments shown by the teacher with a list of elements, the results of the experiment can make us better understand the properties of different metals especially the characteristics of gold.
This is the activity series and it’s a listing of elements, we have elements going all the way down, I want to caution you before we get too far into this, I didn’t write every single element on the periodic table in this activity series, so when you open your textbook, whatever book you’re using, you’re going to find a table of the activity series, that’s what you should use for your problems, because it will have everything needed, this is a good start for our discussion.
But keep that in mind, it’s not a complete listing, so what we have and what it’s going to differ depends on how your book is written, but most books are written like this, the elements at the top of the list are not very reactive and the elements on the bottom of the list are extremely reactive.
So you probably heard that gold is a precious metal and the reason why gold is precious metal is that it doesn’t react with anything, it doesn’t tarnish, for instance, like silver does, let’s find silver on the list, you go down here, silver is a little bit lower on the list, silver likes to tarnish, you ever find a copper.
Copper likes to oxidize, you go down the list, you might find iron, you ever heard of iron oxide, that’s rust that likes to happen, it’s something, something happens to all iron that loves to lose its electrons, so you put iron outside, you’re going to have rust.
But if you go to the top of this list, you see gold is possible for gold to lose to lose electrons, but it isn’t very likely to do that, it doesn’t like to do it, so that’s why gold is precious, because it stays beautiful for 20 years, you don’t have to polish it much, so we have a table at the top of the list which is least active.
In other words, you can think of that is least likely to oxidize or to react or to lose its electrons, as we march down the table, we have more and more reactive things, so we have an arrow and I put this here for you easier to oxidize, that means the things that are more, but lower on the list are easier to oxidize, that means easier and more prone to lose their electrons, that’s what it means the things on the bottom of the list that wants to lose their electrons which means oxidized, which means it reacts the things on the top of the list.
So if you have a reaction with a metal, that’s at the top of the list, in the middle is at the bottom, you can use this list to figure out, if it’s going to happen, it is the bottom line, so one more thing before we tie it all together, we have the oxidation product listed when it does lose its electrons, Gold likes to lose three of them, but that doesn’t happen very often, because it’s very unlikely to happen.
Mercury likes to lose two electrons, silver likes to have a charge of +1 which means it loses one electron, so you can read them all down here, so that can help you predict, let’s look now that we have our Activity series, let’s go and see what’s going on here.
So we have zinc and we have copper sulfate, so we have zinc and copper, so zinc wants to lose its electrons and copper wants to lose its electrons, let’s figure out which one wants to lose this electrons more zinc or copper, so we have zinc here, so put a little mark here, we have zinc here and we have copper up here, so you can tell by this list that because zinc is lower on the list, it’s easier to oxidize which means it wants to lose this electrons more.
So if you have a comparison between something with zinc and something with copper, zinc wants to lose the electrons more, it wants to react more, so when you look at this reaction, zinc is over here neutral, it wants to lose this electron, so does copper.
But it dink wants to lose them even more than copper does, so that means zinc is going to come in, it’s going to push copper out of the way, it’s going to lose its electrons join up here and copper even though it doesn’t want, copper is going to be forced to gain electrons and become neutral, because copper has a positive charge when it’s tied up like this in this compound.
Because of the way the reactions are going on, we force it to gain electrons and become neutral, I want to stress copper doesn’t want to become neutral, if it had a choice, it wanted to lose electrons too, this table copper wants to lose electrons, not as badly as zinc does.
So when we go to the opposite reaction here with copper out here and zinc here see in this location, zinc’s already lost electrons, because it’s bound up like this and this is neutral, so zinc wants to lose its electrons more readily than copper does according to this table.
So that means there’s no way zinc is going to relinquish its spot in this in this compound here, but it’s already lost its electrons, there’s no way copper can come and muscle in and push zinc out of the way and lose its electrons and pushes ink out of the way which has already lost its electrons, because zinc is low or on this activity series zinc is lower on this activity series, that’s the fundamental thing.
I’ll share one more thing with you before we close this lesson up, maybe give you a cool example, here we have this reaction which can happen, you have na plus h2o, so this is sodium and this is water h2o, what do you think is going to happen?
Let’s look and see if anything will happen, remember hydrogen typically likes to lose electrons, I mean that’s what it’s doing here, it lost an electron and oxygens gained two electrons, so inside of this molecule, if you want to think of it in terms of charges which is tough to do, because this is a molecule
But hydrogen likes to have a positive charge it generally does, but sodium wants to lose electrons, also because it’s a metal, so let’s see which one wants to lose its electrons more, when you look at this table, you come down here and you’ll see hydrogen likes to lose and makes a charge of +1 lose one electron.
But let’s go down the list, finally we get the sodium almost at the bottom of the list, sodium not only is it lower on the table which means it’s easier to oxidize more reactive, the most active, it is almost to the bottom of the chart sodium is extremely reactive pure sodium metal, it is extremely reactive, it’s so reactive that you can drop sodium in water pure water and it will react.
Because it wants to lose this electron so much compared to the hydrogen, it pushes the hydrogen out of the way, so what you end up with if you do this reaction is that you’ll end up with hydrogen gas plus in a Oh H sodium hydroxide and you’ll have two here and two here.
So two sodium’s sodium for hydrogen’s for two from there and two there so four hydrogen’s and we have two oxygens two oxygens, so don’t worry too much about the fact of how this happens exactly, but the point is that this thing bumps the hydrogen out hydrogen comes out as a gas, I put a gas there, it comes out as a gas, the sodium goes in there and joins inside here, there’s an AA, there’s an oxygen in there from the water, one of the hydrogen’s sticks around.
So it makes this hydroxide in there, so what you end up with is a basic solution in there sodium hydroxide and you end up with this hydrogen gas, that’s liberated so literally, it’s very dangerous reaction literally, if you take a piece of sodium metal and you drop it in a glass of water, it will release hydrogen gas, it also releases heat and that hydrogen gas starts to catch on fire, so it’s amazing.
If you drop it in there, the metal dances on the surface of the water and it’s like a ball of fire, it’s on fire, because the hydrogen gas comes off and the hydrogen gas catches on fire, because it’s flammable, so the only reason why this works is that sodium is much more reactive and willing to lose its electrons than hydrogen, so that’s one example.
I want to close the section off, we’ll do a couple of more examples in the next section, but I want to make sure you’ll understand the concept of the Activity series, it’s basically letting you predict if a single replacement reaction is going to happen and the way you do that is that you compare the two metals that are involved in your reaction, figure out which one is most willing to lose its electrons and that’s going to basically tell you if the reaction is going to proceed, so you can see gold at the top of list, not so reactive, silver not so reactive.
But as you get down in the copper and lead and tin, you can see that these are the medium weary activities down here at the bottom, the sodium’s and the calcium’s and the magnesium’s, those are reactive things that are typically going to win when you try to react them with something.
Because they want to lose their electrons so badly, they’re willing to give them up all the time, so they always want to be oxidized, so make sure you understand this lesson that you understand the concept of an activity series which relates back to oxidation, that’s why we’re covering it here and then follow me on to the next section where we will get a little more practice with using the activity series to predict whether reactions are going to happen or not.