Video instructions and help with filling out and completing Form 2220 Reduction

Instructions and Help about Form 2220 Reduction

This video is an introduction to oxidation reduction reactions we often abbreviate oxidation and reduction so we just call these redox reactions for short so what is an oxidation reduction or redox reaction here's a quick definition in oxidation reduction reactions electrons move between atoms check out this diagram here we got atom a and atom B and there's an electron moving out of atom a into atom B so this is definitely an oxidation reduction reaction because there's an electron moving between the atoms now we can describe the movement of this electron using the words oxidation and reduction so let's learn specifically what both of these mean reduction is a gain of electrons I know this seems kind of confusing because usually when you have a reduction of something you have less of it we'll talk later about why a gain of electrons is called a reduction but anyway reduction gain of electrons and then oxidation which is a loss of electrons so we got reduction and oxidation what's happening to atoms a and B over here well atom a is giving up one of its electrons it's losing an electron so atom a oxidation is taking place atom B is receiving an electron it's gaining an electron so it atom B reduction is taking place now we can modify these words slightly to come up with terms we use to describe what's happening to the ABS atom a is undergoing oxidation so we can say that atom a is being oxidized atom B is undergoing reduction so we can say that atom B is being reduced so we got oxidation oxidized reduction reduced the big picture here is that reduction is a gain of electrons and oxidation is a loss so I don't know about you but when I was first learning this stuff I found it so confusing why should a reduction be a gain of electrons usually when you're reducing something you're gay less of it so here's one thing that might be helpful to think about that's that electrons have negative charge so as you add electrons to something its charge goes down the more electrons you add the lower the charge so as you add electrons as electrons are gained the charge reduces so that might be helpful to keep in mind to have this make a little bit more sense still these things can be really confusing to remember so here are a couple really great mnemonics first is the term oil-rig this is the name one of those big structures you use to drill for oil Oh il stands for oxidation is loss and RI G stands for reduction is gains it's a really good mnemonic here's another one you might like if you like animals Leo the Lion says ger all right le o stands for loss of electrons is oxidation and ger stands for gain of electrons is reduction so learn one or both of these will be a great way you can always remember what reduction is and what oxidation is okay oxidation and reduction happen in all sorts of chemical reactions there like the super important thing that makes those reactions happen that makes them go so to learn more about this stuff we're going to have to look at an example of a chemical reaction where oxidation and reduction are taking place here's a chemical reaction that we're going to be talking about sodium and chlorine coming together to make sodium chloride table salt now sodium chloride is an ionic compound which means it's made of ions specifically the sodium one plus and the chloride 1 minus ions these two ions stick together because I have opposite charges and opposite charges attract now Na and Cl they didn't always have charges though over here before they combined they have no charge they are two electrically neutral atoms so in order to come together and make sodium chloride these two atoms have to end up getting charges and then they stick together so let's talk about how this happens how they end up getting charges so we start out with Na and Cl here as electrically neutral atoms with no charge and they're on their own they're separate the next thing that happens is sodium gives one of its electrons to chlorine so this is where the charges come in sodium loses one of its electrons so it becomes in a plus one and chlorine gains an electron so it becomes CL minus one now we have two ions with opposite charges what an oppositely charged things do they stick together so these two ions come together and they stick making sodium chloride okay so this is the process where we start from electrically neutral atoms we have an electron transfer we get ions that then stick together so here's the equation that I showed you earlier that describes this process there are a couple things that I could add to this though to make stuff a little clearer check out these numbers that I've written it here in the red these are called oxidation numbers and they give me a sense of what's happening with the electrons and with the charges so above Na and Cl I've written zeros that indicates that these two atoms start out being electrically neutral they have no charge that's what the zero means then on this side of the equation once the sodium chloride have taken on charges I put those charges above each element plus one for the sodium and minus one for the chloride these oxidation numbers help us keep track of how charges chain during a reaction most importantly for this reaction they remind us that sodium and chlorine start out neutral and only end up getting a charge later after this electron transfer takes place so that is oxidation numbers and we'll talk more about those in coming lessons so obviously this is an oxidation