Functional Groups in Chemistry - Online Tutor, Practice Problems & Exam Prep

• Functional groups are recognizable and responsible for compounds' reactivity
• Hydrocarbons contain only carbons and hydrogens
• Functional groups without carbon may contain sulfur, oxygen, nitrogen, or halogens
• Common functional groups without carbon include alcohols, ethers, amines, aldehydes, and thiols
• Functional groups with carbon may contain carboxylic acids, esters, amides, aldehydes, or ketones
• A carbonel group is C double bonded to O
• Different types of hydrocarbons include alkane, alkene, and alkyne
• Benzene rings are also a type of hydrocarbon
• Sulfur, oxygen, nitrogen, and halogens are recognizable landmarks for functional groups without carbon
• Red markings in transcripts represent specific functional groups

Hydrocarbons

Now the functional group represents the part of a molecule that is recognizable and responsible for the compounds reactivity. In this series of videos we're going to go how to identify different functional groups of given compounds. First, we're going to start out with the hydrocarbons. Now hydrocarbons are just compounds containing only carbons and hydrogens, hydro standing for hydrogen and of course carbons for carbons.

If we take a look here, what we have highlighted in red represents that particular functional group. In the first one we have just carbons that are single bonded to one another. We're going to say when we have just a series of carbon single bonded to each other and they're single bonded to hydrogens, this represents what we call an alkane group. So this is an alkane. The chain could get even longer if it wants. So as long as the carbons are single bonded to each other and single bonded to hydrogens, it represents an alkane.

Next we're going to say what's highlighted is 2 carbons. This time, they're double bonded to one another. When we're talking about double bonded carbons, this represents an alkene. And then for the third one, we have our carbons triple bonded to each other. When carbons are triple bonded to each other, that's an alkyne. Now you might notice that we have similarities in names. We have alkanes, alkenes and alkynes.

And then finally what we have here is we have a ring with three double bonds within it this year. We call this a benzene ring, or you may hear it being called an aromatic ring as well. So they're interchangeable terms, benzene ring or aromatic ring. For those of you who plan to go further into chemistry, into organic chemistry, you'll go into greater deaths when it comes to these different functional groups. Now just realize that this first group is only the hydrocarbons. They all have only carbons and hydrogens associated with them.

Functional Groups In Chemistry Example

In this example question, it says identify the type of functional group or groups present within the following compound. So here we have a bunch of carbons and hydrogens, so we know that it's a hydrocarbon. Now let's lookout for double bonds and triple bonds because those seem to be big indicators of the different types of hydrocarbons that exist.

If we take a look here, we have these two carbons double bonded to one another. These two carbons double bonded to one another and then here these two carbons triple bonded to one another. Now remember if you have a triple bond between carbons, that represents an alkyne functional group. And then here these two double bonded carbon groups represent alkene functional groups.

This structure cannot be seen as an alkane because an alkane possesses only single bonded carbons and hydrogens together. So we wouldn't count that as a unique functional group for this compound. So again, lookout for the double bond. Lookout for the triple bond. Those are good landmarks to look for when looking at different types of hydrocarbons within any given compound.

Functional Groups without Carbonyls

In this video, we'll take a look at the functional groups without carbonyls. Now, a carbonyl group represents a carbon double bonded to an oxygen, so it's represented as C=O. Functional groups without a carbonyl group are recognizable by the presence of sulfur, oxygen, nitrogen, or a halogen. Remember, your halogens are in Group 7A, so they're represented as fluorine, chlorine, bromine or iodine. So a good way to remember this is sun, halogens, sulfur, oxygen, nitrogen and the halogens.

If we take a look down here, we're looking at the what's marked in red. That's kind of like a landmark that helps us to identify that particular functional group. So if we take a look here, if you have a single bonded carbon, so the carbon only has single bonds and it's connected to an OH, that represents an alcohol for the next one. If you have single bonded carbons, alright single body carbons, and they're both connected to the same oxygen making C-O-C, then that is an ether.

For the next one, the landmark is the nitrogen. If we have a single bodied nitrogen connected to hydrogen's then that represents an amine. Now typically you'll see nitrogen could have one hydrogen or two or three hydrogens. Next we have carbon connected to X. What does X represent? Well, X is just a placeholder that represents any of the halogens, fluorine, chlorine, bromine or iodine. So if you have a single bonded carbon here connected to one of the halogens, then we call that an alkyl halid. So it's called an alkyl halid.

Then finally, if you have a single bonded carbon, single bonded carbon that is connected to an SH group, then we call that a thial O here. These represent the most common types of functional groups that have sulfur, oxygen, nitrogen or halogen, but no carbonyl group. So keep these in mind when you run across them while looking at different functional groups.

Functional Groups In Chemistry Example

Here the example question says identify the type of functional group or groups present within the following compound. Remember look for your landmark elements sun or halogens.

If we take a look here, we have an oxygen. We're going to say that oxygen looks like it's connected to what, a carbon here and a carbon here. Those carbons, we don't see double bonds or triple bonds connected to them. So they're just regular single bonded carbons connected to an oxygen.

And remember, when we have Coc, that represents an ether functional group. So here our only functional group within this structure would be our ether.

Functional Groups with Carbonyls

We're now going to take a look at the functional groups with carbonyls. Remember, a carbonyl group is just C=O. We're going to say these types of functional groups share some similarities with those without carbonyls. What we have written in red is what that functional group represents. The things around it may change, but as long as you have that portion in red there, that's the functional group.

If we take a look at the first one, we have C=O connected to an OH group that represents what we call a carbasilic acid. So this is a carbacillic acid. For the next one we have C=O connected to O and then connected to AC. That is what we call an Ester. Next we have C=O directly bonded to a nitrogen that is an amide or amide. So both pronunciations are OK. So you might hear it as an amide or an A mide, Same thing.

Next we have AC=O connected directly to an H. We call this an aldehyde. And then finally you have AC=O with a carbon on each side that represents A ketone. So remember, all of these particular functional groups have the presence of a carbonyl group, and what is marked in red represents that specific functional group.

Functional Groups In Chemistry Example

Here we have to identify the type of functional group or groups present within the following compound O . If we take a look look for your carbonyl groups. We have a carbonyl group here. We have a carbonyl group here. Now look to see what they're connected to.

Well, the one on the left, that carbonyl is directly connected to an H. Remember we said if a carbonyl is directly connected to an H, that represents an aldehyde functional group. For the other carbonyl, what is it directly connected to? Well, it's connected to a carbon on this side, but that doesn't tell us much.

It's connected to an OH here because it's connected to an OH. That is also another important functional group, that is a carbasilic acid. So this particular compound possesses 2 carbonyl containing functional groups, one being an aldehyde and one being a carbasilic acid.

Identify the type of functional group(s) present within the following compound.

• A. amine, ketone
• B. amide, alkene
• C. alkene, ketone
• D. amine, ketone, alkene
• E. alkene, amine

Identify the type of functional group(s) present within the following compound.

• A. alcohol, ketone
• B. carboxylic acid, alcohol
• C. ether, alcohol
• D. ester, alcohol
• E. ester, ether