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- Solutions 11

CL-20 and HMX are both powerful explosives. CL-20 produces a more powerful blast but is generally considered too shock-sensitive for practical use. HMX is significantly less sensitive and is used as a standard military explosive. When a 2:1 mixture of the two compounds is cocrystallized, the resulting explosive is expected to be more powerful than HMX alone, but with a sensitivity similar to HMX **(**Cryst. Growth Des. **2012****, **12**, 4311–4314)**.

(a) What are the molecular formulas for CL-20 and HMX?

Hey guys. So for this question it want us to determine the molecular formulas for CL20 and for HMX here, so we just need to count how many carbon it has, how many hydrogens and looks there's nitrogens and oxygens as well, okay? So, hopefully the nitrogens and the oxygens weren't that hard to count, right? Because they are all drawn in. So, let's actually do that first. Now, how many nitrogens do you see? We have 1, 2, 3, 4, 5, 6, right? And then all those nitrogens have another nitrogen attached, right? So, in total we should expect 12, right? So, we have 12 nitrogens. So N12. Now, how many oxygens do we have, well, let's take a look, we have 2, 4, 6, 8, 10 and 12, so it's the same amount of oxygens as we do nitrogens, for the formula it becomes N12O12, but are we done? Well guys, it's actually carbons drawn in at every corner of this ring here and there's also hydrogens as well on those carbons, because remember carbon wants to make up to four bonds, if it only has three that means it contains a hydrogen. So, let's go ahead now and I want you guys to try to find the carbons here, it's where you see two lines meet, so in the corners of these molecules and what I mean by that is as you see right here this is going to indicate where the carbon is as well as here and you see any other ones? Well, actually back here there's some more carbons as well.

Now, there's actually two more and I want you guys to try and find them, remember is where these lines meet up, so the ones that I'm talking about are the ones right here and right here and what you see is that there's a total of six carbons, so we can write in C6, and all these carbons, they only have three bonds to them and what that means is that they are going to have a hydrogen as well, so our formula becomes C6H6N12O12, okay? Let's move on to the next one HMX, Now, here it gets very easy to spot the nitrogens and oxygens, so we have 1, 2, 3, 4, 5, 6, 7, 8, nitrogens, so N8, and how many oxygens do we have? The same number, right? We have 2, 4, 6, and 8, so our formula now is up to N8O8, but again, what are we missing? The carbons and hydrogens, so remember, is where those corners meet up and now notice that carbon has only two bonds to it, so how many hydrogens should you expect that these carbons? 2, right? So, let's go ahead and highlight where our carbons are, we have, 1, 2, 3, and four carbons, so C4 and how many hydrogens now? Remember all it is two bonds so every carbon is going to have two hydrogens, so we should expect double the amount of hydrogens than carbons, so now our molecular formula is C4H8N8O8, alright guys? So, hopefully you guys were able to come up with the molecular formulas for our CL 20 and also our HMX. Alright, so let me know if you have any questions.