Determine whether or not each metal, if coated onto iron, would prevent the corrosion of iron. a. Zn

Video transcript

hey everyone in this example, we're asked whether coating iron with tin metal will prevent the corrosion of iron. So what we should recall is that to prevent the corrosion of iron, the metal has to be more easily oxidized and that would correspond to us recalling that the lower the self potential value of that metal that will correspond to the metal oxidizing first A. K. It's more easily able to be oxidized. So we're going to write out our full reaction where we have middleton reacting with the iron three plus cat ion, whereas a product we would form the 10 2 plus cat ion as well as solid iron. Now, because this we should recognize as a redox reaction, we're going to write out or half reactions and that's going to come from our reactant. So for our first reactant we have solid 10 Which forms our product 10 2 plus and we should recognize that we have a net charge of plus two on the product side here, whereas on the reactive side we have a net charge of zero. So we want to cancel out this net charge of plus two by adding two electrons to the product side here. For this half reaction. And because we added electrons to the product side here, we would recall that this is going to occur as a reduction or sorry, as a oxidation half reaction. When we add electrons to the product side, that reaction will always be an oxidation. Now looking at our second half reaction, we have our second reactant which is the iron three plus cat ion which forms as a product, solid iron. And so we should recognize that we have a net charge of plus three on the reactant side. Whereas on the product side we have a net charge of zero. We want to cancel out this net charge of plus three. So we're going to expand our reactant side here by canceling out that plus three charge by adding three electrons. And so what this means because we recognize that we added three electrons to the reactant side. We would recall that this means that this half reaction occurs as a reduction since electrons were added to the reactant side. And so now that we've identified our oxidation and reduction half reactions were going to recall that our oxidation half reaction occurs in our voltaic cell at the node where our reduction half reaction occurs in the voltaic cell at the cathode. And so now we're going to recall upon our table of standard reduction potentials. So we would find this table either online or in our textbooks and we would see that for the oxidation of our 10 2 plus cat eye on, we're going to have a self potential value equal to negative 0.14 volts. Whereas for oxidation of the iron three plus catalon, we would have a cell potential according to this table equal to negative 0.36 volts. And so what we can say is that -0.14V is less than negative 0.036V. And so therefore our solid tin will be oxidized first or more more easily oxidized. And so yes, our final answer is yes. 10 will tin metal will prevent the oxidation or sorry, the corrosion of iron. And so this here yes, will be our final answers because tin will prevent the corrosion of iron. So what's highlighted in yellow is our final answer. So I hope that everything I explained was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.