- Concept Videos
- Solutions 7

Under controlled conditions at -78°C it is possible to fluorinate 2,2-dimethylpropane to yield (CF_{3})_{4}C. Write a balanced chemical equation for this reaction.

Hey everyone. So, in this question is our job to write on a balanced equation for 2,2-dimethyl propane undergoing fluorination. Alright, so that's why we have our fluorine there, if it was chlorination it would simply be Cl2, bromination Br2, okay? And note that 2,2-dimethyl propane maybe you're a little bit used to seeing it like this, okay? where at position two we have our 2 methyl groups. Now, this is just written in a formula that represents that and this is going to be a formula that's kind of similar to this one with the fluorine groups what you can see is this was given to us, I rewrote our 2,2-dimethyl propane in the same form and what you notice is that every one of our hydrogens got replaced by a fluorine, okay? So what is our job to do? is just balance out this equation and then of course our hydrogens are going to combine with the fluorine for another byproduct, alright? So, the way I would do this is we have five carbons in our 2,2-dimethyl propane, right? So I would write down here C5, I would make sure I have five carbons in the next one, which I do. So, now let's balance on our hydrogens if this was just a regular alkane we know it's going to be 2n plus 2 for the number of hydrogens, we plug in an S5 for the number of carbons we have and what we would expect to get is 12, so you can count them up, hopefully I didn't confuse you, just take you back to where we calculated the ihd and how we figured out how many hydrogens we have but we have 12 hydrogens, okay? And of course they come from all the methyl groups because there's not in the center at that carbon? Well, in a balanced chemical equation we need to have the same number of atoms on both sides, so what should we do to make this gear up towards the correct answer? Well, we see hydrogens located over here and we know we need to have 12 of them. Now, the 12 is going to not only apply to our hydrogens but our fluorines, right? And we have 12 fluorines here, plus the 12 here, so we're going to need 24 of these, the only way to do that is to add in a 12 there, okay? So the last value, the last atom that we need to fill in with our fluorine and there's 24 of them. So, here is C5, let's rewrite that C5, H12 here, there's 12 of them and 24 more fluorines, okay? And then of course these values in here we don't have to write them in, what we know it's just going to be a 1. So, our balanced chemical equation is going to look like this, where we have a 1 in the first spot a 12 a 1 and then another 12, okay? So, all of our atoms should match up. Alright guys, so hopefully this makes sense but if not, let me know if you have any questions.