Oxidizing Agents - Video Tutorials & Practice Problems

Oxidizing Agent - Permanganate Ion

So here we're taking a look at the oxidizing agent of permanganate ion, we're gonna say the most commonly used oxidizing agent. Ty trains include our permanganate ion which is M. N. 04 minus Siri. Um four ion, Die Chrome eight ion as well as our tri iodide ion. Now we're going to say here that an an elite also sometimes called a tie trend that is a week reducing agent requires one of these strong oxidizing agents during penetrations. That's because it goes in terms of your chemical thermodynamics by using a strong oxidizing agent, we're going to basically push the equilibrium towards the product side to ensure that are an elite or tight trend is successfully oxidized by these titans. Now we're going to say that our permanganate ion itself is difficult to isolate because it can easily oxidize its acquis solvent. So water to form manganese for precipitate. Now, for those of you who remember the lab where you deal with permanganate ion, remember it has a dark purplish color if you get it on your hands or skin it's gonna stain them and it's incredibly difficult to get that color out. Also remember that depending on the labs that you've taken, sometimes you have to prepare your permanganate solution and remember that you have to keep it in a place that's dark absent of any light because light itself could somehow cause some of this permanganate ion to be converted into this manganese for oxide and that's the reason why although permanganate ion is a strong and great oxidizing agent, the whole storage of it makes it incredibly difficult to use. And usually we'll go with other types of oxidizing agents instead. Now we're gonna say here in order to isolate the oxidizing agent of permanganate ion. Um we must catalyze it with either acids, basis manganese for oxide or manganese to ion. These helped to push the equilibrium towards the side that helps to generate the permanganate ion here below we have a typical half saw reduction reaction um within an acidic environment for permanganate ion here we have our permanganate ion reacting with eight moles of hydrogen ion here it absorbs five electrons. As a result of this it becomes manganese to ion and water. If we were to increase the amount of permanganate ion, we would thereby force the equilibrium to go in the reverse direction. By this process will help to make more permanganate ion. So by increasing the amount of this, we could help to force more of this being formed. If we were to um expose it to light, light would cause uh catalytic response which would help to make more magazines for um precipitate meghan is for oxide. Precipitate. If we used a base adding a base would help too reduce the amount of H plus ion, we need to replenish that so that again the reaction would shift in the reverse direction to replenish it and as a result create more per magnate. On the other hand, if we were to increase the amount of acid we would increase the amount of H plus ion. And following the chandeliers principle, we have to move in the four direction to get rid of the excess acid added. This would only help to diminish the amount of your permanganate ion. So just remember these are the four main strong types of oxidizing agents. The first two permanganate ion and Syrian four ion are actually the strongest out of the four. The other two are weaker, but with them being weaker, that gives them an advantage because they become more stable. So just remember when it comes to your permanganate ion, we're going to say it's incredibly difficult to isolate. So it has to be handled with extreme care. Go to the next video and see the steps necessary to standardize and prepare the permanganate ion.

Oxidizing Agent - Permanganate Ion

So as we said before, your permanganate ion represents one of the strongest oxidizing agents that we can utilize within a given redox filtration. However, it's incredibly difficult to obtain a pure permanganate ion solution. That's because regardless of what you do, there's gonna always be at some point. Some magazines for oxide precipitate that's found within the solution. And we'd say here the equation would be four moles of permanganate ion, Plus two moles of water would break down and do a reduction to produce four moles of magazines for oxide solid, you would produce some oxygen gas as well as some hydroxide base. So there's a constant struggle to keep your pure permanganate ion solution and minimizing the amount of magazines for oxide, solid or precipitate that's being formed. Now, what we can do is we take a solution of your permanganate ion solution which is most likely gonna still have some solid within it. We'll have to boil it and then over time filter out this magazines for oxide so that we're left with a stable permanganate solution, we have to make sure we contain the solution within a dark glass so that light doesn't catalyze the reaction and help to produce even more precipitate. Usually when we make permanganate ion solution within a lab, we're told to store it away in a dark place so that light doesn't reach it so that this catalyzed process doesn't occur. Now, we can pairing it with a reducing agent such as iron two or oxalic acid can be used to help with the standardization process of your permanganate ion solution. Now the standardization will not last for long remember because naturally your solid magazines for oxide precipitate is being created. So you should continuously make a new amount of standardized permanganate solution to make sure you get the most accurate measurements, as well as calculations when using it. Now, when it comes to your mag unease, when it comes to your iron to ion. In the standardization process, we have our per magnate ion reacting with it in an acidic environment. In the process we create our magnets to ion and we create five iron, three ions. So iron goes from being plus two to being plus three. So we know it's being oxidized by the strong oxidizing agent of permanganate ion. In the process of this oxidation, the permanganate ion itself is reduced to this M and two plus form as well as the creation of four moles of water. Now we could also standardize our permanganate ion solution again by using oxalic acid here, it's oxalic acids with an acidic environment. Again, we're gonna make magazines to ion. So it's being reduced to magazines to ion. Now we'd also make carbon dioxide, gas and additional moles of water liquid. Now when it comes to permanganate ion unlike the other oxidizing agents because it's so hard to keep a pure permanganate ion solution. We'd say that permanganate ion cannot be used as a standard primary standard. However, because there is such a difference in color when it comes to permanganate, which is purplish in color and uh, manganese to ion, we could use it as its own indicator. We're gonna say near the end point, we're gonna get a slight pinkish color. That will tell us that we have an excess of permanganate ion. For those of you have done labs dealing with permanganate ion, you know that you're doing attrition and drop by drop, you're adding permanganate ion solution uh to your an elite. And there comes a point where you dropped just enough that the solution turns slight pink. That tells us we've reached the end point. If we were to continue to drop additional permanganate ion, the solution would turn a dark purple. So although permanganate ions cannot be used um for our primary standards, because of how hard it is to maintain and prevent the formation of precipitate in the form of magazines for oxide, it could be used as its own indicator because here, permanganate is purplish in color or violet, dark violet And Manganese two Ion is colourless. So that's one benefit in terms of using permanganate ion, you can clearly see where the endpoint could be formed. Now that we've talked about the standardization process, move on to the next video where we take a look at the different types of oxidation reactions that are possible with a strong oxidizing agent such as permanganate ion

Oxidizing Agent - Permanganate Ion

So recall that the natural color of our permanganate ion is a dark purple violet color. Now, depending on the ph of the solution, it can influence the type of products that we form and the color transitions that will result here, we're going to say in a highly basic solution. So they have phs that are equal to or greater than 12. They have concentrations that tend to be one molar greater. We're going to say here that are pro magnate ion is reduced to the magnate ion. This magnate ion has a greenish color to it. So here we have a transition in color, however violet and green, it's hard to see exactly where the end point is reached in terms of going from a purplish violet color to that greenish color. Next we're gonna say in highly acidic solutions. So these have phs that are equal to or less than one. We're gonna say permanganate ion is reduced to the manganese to ion here, manganese to ion is a colorless ion. We're gonna say here in acidic environments, we can say that our permanganate ion can serve as its own indicator because here we go from a violet color. Well we go from a a colorless solution and as we're tight trading with permanganate ion, it would transition towards a light pinkish color once we reach our end point. So here in a highly acidic environment we can use permanganate ion as an oxidizing agent as well as our own indicator. Finally, we can say that in a neutral or basic solution, the permanganate ion is reduced to manganese. For oxide precipitate. so it's reduced to this solid here. This solid here has a brownish color, so realize that our pro magnate ion is one of the strongest oxidizing agents that we have. But in terms of standardizing and preparation as well as storage, it's incredibly difficult to use. So we usually rely on the other strong oxidizing agents as other ways of dealing with redox tight rations. Now, of course, at some point, you will come into contact with using permanganate for some type of tip tray shin process if you haven't already realize that it has its usefulness. But again, it's incredibly difficult to use and therefore we tend to stay away from it unless absolutely necessary.

Oxidizing Agent - Cerium (IV) Ion

So now we take a look at the serie um for ion as our next strong oxidizing agent. Now like other strong oxidizing agents, it needs to be standardized in order to be stored or to take part in additional reactions. Now we're going to say it is less commonly used because of the cost in preparation, storage and utilization. Now, although permanganate ion is hard to maintain because it tends to go to its precipitate form, it would be a better option than the serie um For eye on syria for ions process is just too time consuming and also costly. Remember we also have the other two strong oxidizing agents that we can later talk about in terms of their utilization. Now we're going to say here that we have Siri um four ion being reduced to produce our Siri. Um Three ion, we're gonna say that the Syrian three ion is more stable in terms of its oxidative state out of the two ions, this means that it drives the equilibrium towards the product side. That means that my Siri um four ion greatly wants to accept an electron to become this form here as a product. That's what makes it such a good oxidizing agent. By putting cereal for ion next to a an elite. It will quickly try to remove an electron from it to become this more stable ion here. Now in terms of the standardization process for Siri um there are multiple ways to do it. Two common ways. One is to use it from a primary standard of Syrian for ammonium nitrate which is given by our formula here and it's dissolved within an acidic media. So here we have one molar of sulfuric acid solution. In addition to this, we could have from syria for hydroxide. Being standardized against an iron two or oxalic acid solution and then using for heroin as the indicator to determine what the endpoint would be. Now here, their equations can be given as these two bottom ones here. So by using our serum for ammonium nitrate, we tend to use that particular compound to give us this serie um for ion, it's a useful compound to help us determine the amount of iron within a given unknown sample. And that's why we have iron to ion within our first equation here, iron two goes from being plus two to being plus three, it is lost an electron and that electron has been taken by the Syrian for ion. Again, it does this because it wants to form the more stable Siri. Um three ion. Now, in terms of our serum for hydroxide, we could use our oxalic acid here and we'd say that it produces again, we're gonna have Siri um three ion, the more stable ion but now two moles of it. We produce two moles of carbon dioxide as well as two moles of hydrogen ion. Now, in terms of oxidation reactions, we're gonna say a common reaction involves the reaction of ferris, ammonium sulfate, hex a hydrate, which is given by this compound and Siri um for ammonium nitrate, which we saw up above, we're gonna say the net equation is the equation that we saw just up above here. And the other common type of reaction that deals with Syrian for ions involves melodic acid. Here are melodic acid will be reduced in the process. We're actually will be oxidized in the process Siri. Um here is reduced, it's reduced to Siri. Um three ion melodic acid is oxidized here to formic acid during this oxidation process where melodic acid becomes formic acid. We also have the generation of carbon dioxide gas and six moles of hydrogen ions as products. Now remember permanganate ion and Siri um for ion represent the two stronger oxidizing agents out of the common four that are typically used, they both have their strengths but as well as their weaknesses, serum for ion is more stable if it can be created in terms of a solution. However, the process in making it is costly and time consuming permanganate ion is not as expensive in terms of making the solution, but again, it's hard to maintain permanganate ion solution because it always wants to create some of that magazines for oxide precipitate. So you always have to handle it with great care. So when we look at these two oxidizing agents, they both really are trying to remove an electron from our analyzed species to become a more reduced, more stable form. So we'll continue on with our discussion of other strong oxidizing agents. And keep in mind that all of these here are just helping to oxidize a given an elite in order to make a more favorable ion in the process.

Oxidizing Agent - Dichromate Ion

So now we take a look at our next oxidizing agent, which is our di chromite ion. It is normally found in as a form of potassium di chrome eight, with the potassium ion being more of a spectator ion. Now we're gonna say here that the dye chromite ion is not as strong as an oxidizing agent like Siri um four plus or permanganate. But its advantages are because it's not as strong, it's more stable, therefore can be used as a primary standard. Now, disadvantage of it not being as strong as Siri um four plus ion or our permanganate ion is that it wouldn't work with weaker reducing agents. Now we're gonna say that it's reduction half cell reaction within an acidic solution can be seen as di chrome eight plus 14 moles of H plus ions are reduced with six electrons to produce two moles of chromium three plus ion plus seven moles of water. Now, in terms of our di chrome eight and our chromium three, we can say that di chrome it has an orange tinge to it orange color, whereas chromium three plus is green. The thing is, these colors are not different enough for us to really see the difference. So we can't use di chrome it as its own indicator. Like we would with permanganate. Now we're going to say here that diphenyl amine self symphonic acid or diphenyl Ben's iodine cell phonic acid are the preferred indicators to discover the end point here. With the overall equation is going to be monitored by our caramel and platinum electrodes are two types of reference electrodes. Now we're gonna say here that the diphenyl, amine, symphonic acid represents the reduced form. It is colorless and then the oxidized form would actually appear as red violet. So we'd see that color change in terms of the indicator. And once that color change happens we'd be able to spot the endpoint in terms of our redox detraction. Now, once placed into a basic solution, di chrome eight is converted to chrome eight ion. So here we have our chrome eight ion here That's been produced because die Chrome eight was thrown into a basic solution here. The Chrome eight ion here can react um with four moles of H 20 liquid to give us three electrons involved. This produces chromium three hydroxide plus five hydroxide ions. This here is a process in terms of its standardization of our di chromite ion. We're creating a form that's more stable and easier to store for later use. So remember although the dye chromite ion is not as strong as Siri um four plus ion or permanganate, it does have its advantages by being weak. It can be more safely stored for longer periods of time and it can be used as a primary standard click onto the next video to see the different and common types of oxidation reactions that approach that occur with our di chromite ion

Oxidizing Agent - Dichromate Ion

so many of the oxidizing reactions that happen with our di chromite ion occur within the field of organic chemistry. Now, a lot of reactions dealing with this particular oxidizing agents has to do with alcohol is being oxidized here. We're going to say that primary alcohols can be oxidized into Aldo hides. So a primary alcohol here we could have is this type of primary alcohol ethanol. Now here when we use our decrepit ion, it can be oxidized into an alga hide. So here are ethanol will be oxidized. Remember in AL to hide is basically a carbondale group which is c double Bondo single bonded to a hydrogen. So that is what makes this an al to hide here, we can say that this Aldo hide would be ethanol or a Seattle al to hide. Now under more stringent conditions we can change this into a carbon silic acid so we could increase the heat, increase the concentration of our decree made ion. That would force this to continue its oxidation process and become a carbon silicate acid. So this portion here is our car basilica acid here. This would be called phenolic acid or by its more common name acetic acid. Now, secondary alcohols can be oxidized to ketones. So a secondary alcohol that we could have. So here we have to open all, we use this oxidizing agent of di chrome eight and that changes it into a ketone. Remember the feature of a ketone? It is a carbon eel, so see double Bondo With a carbon on each side. So here two propane all becomes to prop unknown or just prop unknown or by its common name, acetone. Here, tertiary alcohols like any tertiary alcohols, they cannot be oxidized by any form of oxidizing agent because it would require a cutting of a carbon carbon bond, which energetically is highly in favored because there's too much of a cost in energy needed to do it. So, just realize here again, dia chromite ions are not as strong as some of the other oxidizing agents, such as Siri, um for ion or permanganate ion. But it has a lot of use in terms of organic chemistry when we talk about the oxidation of alcohols as well as Aldo hides under more stringent conditions.

Oxidizing Agent - Triiodide Ion

So tri iodide ion represents the weakest of the four strong oxidizing agents because it's the weakest, it only really works when we're using a stronger reducing agent. Now we're gonna say it's half cell reduction reaction can be seen as your iodide ion absorbing two electrons to be reduced into two iodide ions. So here we're gonna say molecular iodine though, so I two is slightly soluble in an aqueous solution. Now we have to make it more soluble. So what we do is we combine the iodide of the molecular iodine with one iodide ion. They combined together to give me my tri iodide ion here, which is much more, much more polar and therefore much more soluble within an acquis solvent like water. Now this creates the new reduction reaction as I three minus plus two electrons, gives me three i minus. So that's my new reduction half reduction reaction. Now, in terms of standardization, we'd say a solution of trying to diet is normally I'm normally going to be normalized by N A two as 203 and here we're using Starch as our indicator for the tri iodide ion here with the president of iodine. Starch would go black when you use it as a as the indicator to spot the tri iodide ion. Now we're gonna say the newly created iodine solution is colorless. But with exposure to air, the iodine, I will undergo oxidation to the yellow tri iodide ion. So basically if we expose this reaction to air, it'll move in the reverse direction to create more of this tri iodide ion here and that is yellow in color. So that's a way of testing the sea. Do we have a pure sample of just your ID ID solution or did it move in reverse to create more of the tri iodide ion. Now, in terms of oxidation, the most common type of oxidation we cover deals with a sabic acid otherwise known as vitamin C. We call it the biological antioxidant because its role is just as a reducing agent. Now we're gonna say here that I dine quickly oxidizes acerbic acid and it's gonna generate D. D. Hydro acerbic acid. Here. We can see our equation as this here. So as a result of this we oxidize our acerbic acid which has this formula because of molecular iodine. And we create the new form here of D hydro acerbic acid. If we look at the changes done, we can see that we've lost these hydrogen is here As a result result of losing those two hydrogen, you've created two new carbon Neil groups. Remember, within biological systems, oxidation can mean two things, oxidation can mean the loss of hydrogen or it can mean the forming of bonds with phosphorus oxygen, nitrogen, sulfur or a halogen. So basically the formation of a bond with something that is electro negative. So here the oxygen's have lost hydrogen and these carbons here, they've helped to make new bonds with the oxygen's. So that's what represents an oxidation. So, remember your four different types of oxidizing agents vary in strength, stability, as well as creation. So, based on the situation and lab different ones will be required here. Remember we have our serum for ion as well as our permanganate ion being the strongest, followed by our di chromite ion. And finally, we have our tri iodide ion being the weakest of the four oxidizing agents.