Alkane Reactions - Video Tutorials & Practice Problems
Get help from an AI Tutor
Ask a question to get started.
1
concept
Common Types of Alkane Reactions
Video duration:
2m
Play a video:
Now, when it comes to Alcaine reactions, realize that alkanes are the least reactive of the hydrocarbons. And in fact, they only do two major types of reactions. Our common types of reaction are combustion and halogen nation. Now combustion we know from Gen chem. We say here that the simplest type of combustion reactions involve a hydrocarbon reacting with oxygen to produce carbon dioxide and water. Now halogen nation is something new. Well, this represents a substitution reaction where bromine or chlorine replaces one of the hydrogens on the alkane. Now, here it requires heat or UV. Light. Here we represent UV. Light as HV. And what it does here is it, it's to break the bond between halogens and that halogen then attaches itself to the alkane. So if we take a look here, we have a alkane halogen reaction. Here we have our alkane in the form of methane. It's reacting with X two X. Here again, could represent bromine or chlorine. So this is CL two or BR two through the use of heat or HV, ultraviolet light, we split this X two into two pieces. And then what happens is that one of them substitutes out this hydrogen. So now we'd have an X here, oops X here and then we'd still have an additional X hanging around and this H just got kicked out. So they would combine together to give us HX here. Now, when it comes to this, we're going to say that all cans can be mono substituted and that just means only one hydrogen is substituted or they can be poly substituted where more than one hydrogen is substituted. So pay close attention to the question being asked of you. Are they asking for a mono product or are they asking for a poly product? If, depending on what they ask, you can get different results in this particular one. We're doing a mono halogen, we're just replacing one hydrogen with a halogen. And in the end, we make an alk haid as a product.
2
example
Alkane Reactions Example
Video duration:
2m
Play a video:
Here it states what are the major products of the following halogen nation reaction? Assume monos substitution, right? So if we take a look at this, we know that there's ach three here and ach three here, there is Ach two here and ach two here. And then here we just have another ch two. Now, you might notice that I'm trying to do some type of symmetry here. This is a pentane chain, it has symmetry in it. I'm showing that there's this red carbon on this end and this red carpet on this end that's telling me that they are the same meaning. Remember in this type of reaction, we're gonna substitute out one hydrogen for chlorine. If I put the chlorine on either end, it give me the same exact product, both of them will be called one chloral Penta. So let's actually show that right. So remember this is just substituting a chlorine for one of the hydrogens. And if we were to name this, this would be 1234512345, we start numbering from the end with the substituent in the form of chlorine. Both of these will be one chloral pentane. Since they give the same name, they're the same molecule. So just focus only on one of them. This would just be a redundancy. Same thing with the ones in blue. If I put the chlorine on either one of them, they both would give me two chloral Penta. So only show one of them. So this would be another major product. And then finally the one in the middle, if I put a chlorine on that one, that one's unique because putting one on that one would give me three chloral Penta. So here we get three major types of products and, and that's the way you're able to determine how many possible products you can make, add the chlorine to different positions and then name those molecules that you've created. If they had the same name, then they represent the same molecule. You don't need to show more than one. OK? Unique names, equal unique products. OK. So here we have three major products from the mono chlorination of pentane.
3
Problem
Problem
Determine the major product(s) of the following alkane reaction. (Assume monosubstitution.)
A
B
C
D
Do you want more practice?
We have more practice problems on Alkane Reactions