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Example Questions
Example Question #1 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Aldehyde
Ester
Ketone
Acid anhydride
Carboxylic acid
Aldehyde
Aldehydes are carbonyls with one R-group and one hydrogen attached to the carbonyl carbon.
Example Question #2 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Ester
Carboxylic acid
Acetal
Ketone
Aldehyde
Ketone
Ketones are carbonyls with two R-groups attached the the carbonyl carbon.
Example Question #2 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Ester
Acid anhydride
Acid halide
Amide
Carboxylic acid
Acid halide
This is an acid halide, were X is any halogen (group VII). They are the most reactive of all the carboxylic acid derivatives.
Example Question #3 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Ketone
Carboxylic acid
Ester
Acid anhydride
Aldehyde
Carboxylic acid
Carboxylic acids are composed of one R goup and a hydroxy group bound to the carbonyl carbon. The hydroxyl group gives the molecule acidic properties.
Example Question #5 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Acid anhydride
Ester
Acetal
Hemiketal
Aldehyde
Hemiketal
This is a hemiketal. Hemiketals are formed from the reaction of a ketone with an alcohol. The alcohol attacks the carbonyl carbon, reducing the double bond and adding a hydroxyl group.
Example Question #6 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Hemiketal
Ketal
Acid anhydride
Acetal
Hemiacetal
Ketal
Ketals have two -OR groups bound to a central carbon. The R groups attached to the oxygens are not necessarily the same. Ketals result from the reaction of a ketone with two equivalents of alcohol.
Example Question #4 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Acid anhydride
Ester
Carboxylic acid
Acetal
Hemiacetal
Acid anhydride
Acid anhydrides are relatively reactive, since they have a fairly good leaving group (the conjugate base of a carboxylic acid) [COO-]. They are formed by reacting two carboxylic acids via dehydration synthesis.
Example Question #5 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Amide
Ether
Amine
Imine
Ester
Amide
This is an amide. It is very unreactive since its leaving group is the conjugate base of an amine [HNR-].
Example Question #6 : Identifying Carbonyl Compounds
Identify the given organic functional group.
Ketone
Ester
Ether
Carboxylic acid
Aldehyde
Ester
Esters are relatively unreactive since the leaving group is an alkoxide ion (OR-), which is the conjugate base of an alcohol (a relatively weak acid).
Example Question #1 : Identifying Carbonyl Compounds
How many sigma and pi bonds, respectively, are there in the given molecule?
pi bonds, sigma bond
sigma bonds, pi bond
sigma bonds, pi bond
pi bonds, sigma bond
sigma bonds, pi bond
To answer this question, it's important to recall what sigma bonds and pi bonds are. Sigma bonds are the result of overlapping s orbitals, and are contained in all bonds. Pi bonds, on the other hand, are the result of p orbitals overlapping.
Double bonds between atoms consist of one sigma bond (from overlapping s orbitals) and one pi bond (from overlapping p orbitals). Triple bonds, though not shown in this molecule, consist of one sigma bond and two pi bonds.
In the molecule shown in this question, we can recognize the following bonds:
1 carbon-oxygen double bond, which is equal to one sigma bond and one pi bond
2 carbon-carbon single bonds, which equates to two sigma bonds
6 carbon-hydrogen single bonds, which equals six sigma bonds
Adding these up, we obtain a total of nine sigma bonds and one pi bond.
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