氧化还原方程中有多少电子转移-概念

H So I'll actually show you two ways.



年代 So then what we'll do, is we'll break it into half reactions. So the first method is to use Half-reaction method.



年代 Then we'll match up the Br- with the BrO3-. Then you just follow your steps.



s So all we need to do is balance out the charge for the first half-reaction with Copper. So we have the electron on the reactant side.



F You need to have 6H+ to balance out the Hydrogens. Then you double check the charges. Then so we need to add 6 electrons to the product side of this second half-reaction to make it, so that they are equal charges.



s So that means that the first half-reaction we need to multiply everything by 6. So to multiply everything by 6. Take 6, another 6, and another 6. So now we just add them up.



年代 During the course of the half-reaction, we figured out that 6 moles of electrons were transferred. So that is the long way. That's if you have an unbalanced Redox equation that you're given.



N Here is the trick. So what we'll do is, take a look at the number of atoms of the things that you have oxidized or reduced.



年代 That's identical on both sides. It has to be. You have 1 atom of Bromine, and that's identical on both sides. So 6 and 1, between 6, and 1, the lowest common multiple is 6. So that means that 6 moles of electrons were transferred. So you just take the lowest common multiple between the number of atoms of each of those particular elements that got oxidized or reduced, then you got your answer.



年代 So if you take a look here, let's try this one. So let's do another example. We have 2Al + 3Cl2 yields 2AlCl3.



年代 So 6 moles of electrons were transferred in this way that we balanced the equation.



我 You'll find that 6 moles of electrons were indeed transferred during the course of this reaction.



年代 Just find the number of moles of atoms; those are things that get oxidized and reduced. Then you got the lowest common multiple. You end up with the number of moles of electrons transferred. So that shortcut will hopefully save you a lot of time, and make your life a little bit easier. Have a good one.