Organic Chemistry- Carboxylic Acids Flashcards
Carboxylic acids with _____ and _____ are some of the most reactive organic molecules on test day.
Carbonyl and hydroxyl groups
Carboxylic acids are found in what?
In soups, oils, preservatives, skin care products, clothing, and amino acids
Carboxylic acids often have strong what?
Unpleasant odors
What are examples of carboxylic acids with strong odors?
Acetic acid (Vinegar) Propionic acids (swiss cheese) Butyric acid (rancid butter and body odor)
What makes carboxylic acid so interesting and versitile?
They’re acids, so they give away protons– particularly because when they do so, the reamining negative charge resonates between two oxygen atoms, making the anion very stable. Most acidic compounds encoutered in organic chemistry, with pKa between 3 and 6. Carboxylic acids are also excellent at hydrogen bonding, which results in large intermolecular forces and high boiling points.
Finally, carboylic acids are ubiquitous in nature and synthesized by all living organisims.
What does a carboxylic acid contain?
Both a carbonyl and a hydroxyl group, bonded to the same carbon
Why are carboxylic acids one of the most oxidized groups?
It has three bonds to oxygen atoms, making it one of the most oxidized functional groups encountered in organic chemistry
Carboxylic acids are always what?
Terminal groups
In the IUPAC system, how are carboxylic acids named?
By adding the suffix -oic acid to the parent root when the carboxylic acid is the highest-priority functional group. When this is true, the carbonyl carbon becomes carbon number 1
What is the common name of methanoic acid?
Formic acid
What is the common name of ethanoic acid?
Acetic acid
What is the common name of propanoic acid?
Propionic acid
How are cyclic carboxylic acid named?
By listing the cycloalkane with the suffix carboxylic acid
How are salts of carboxylic acids named?
Beginning with the cation, followed by the name of the acid with the ending -oate repalcing -oic acid.
Which carboxylic acids are common in biological systems?
Dicarboxylic acids
What do dycarboxylic acids contain?
Carboxylic acid group on each end of the molecule
What is the smallest dicarboxylic acid?
Oxalic acid with two carbons
After oxalic acid, what are the next 5 straight-chain dicarboxylic acids?
Malonic, succinic, glutaric, adipic, and pimelic acids
In the IUPAC system, how are dicarboxylic acids named?
They have the suffix -dioic acid
What is the IUPAC name for oxalic acid?
Ethanedioic acid
What is the IUPAC name for malonic acid?
Propanedioic acid
What is the IUPAC name for Succinic acid?
Butanedioic acid
What is the IUPAC name for Glutaric acid?
Pentanedioic acid
What is the IUPAC name for adipic acid?
Hexanedioic acid
What is the IUPAC name of pimelic acid?
Heptanedioic acid
What is an example of cyclic carboxylic acid and carboxylic acid salt?
1-chloro-2-methlcyclo-pentane carboxylic acid (Cyclic) sodium hexanoate (Salt)
Many physical properties of carboxylic acid are similar to what? Why?
To aldehydes and ketones because they both contain carbonyl groups
What makes carboxylic acid different from aldehydes and ketones?
The additional hydroxyl group permits carboxylic acids to hydrogen bond and provides another acidic hydrogen that can participate in reactions.
Why are carboxylic acids polar?
Because they contain a carbonyl group
Why can carboxylic acids form hydrogen bonds?
Because they contain a hydrogen bonded to a very elecronegative atom
Why do carboxylic acids display strong intermolecular attractions?
Because both the hydroxyl oxygen and carbonyl oxygen can participate in hydrogen bonding.
Carboxylic acids tend to form what?
Dimers
What are Dimers?
Pairs of molecules connected by two hydrogen bonds.
Multiple hydrogen bonds do what?
Elevate the boiling and melting points of carboxylic acids past those of corresponding alcohols.
Boiling points also increase with what?
With increasing molecular weight
What is acidic in the carboxylic acid?
The hydroxyl hydrogen of a carboxylic acid
What happens when the hydrogen is removed from the carboxylic acid?
This results in a negative charge that remains after the hydrogen is removed and resonance stabilization occurs between both of the electronegative oxygen atoms.
Delocalization of th enegative charge results in what?
A very stable carboxylate anion
The more stable the conjugate base, the easier it is for _______? And thus, the _________.
For the proton to leave, and thus, the stronger the acid.
What is the pKa value for ethanoic acid?
4.8
What is the pKa for propanoic acid?
4.9
How does carboxylic acid compare to strong acids?
They do not compare to strong acids like HCL with a pKa of -8 or HSO4 with a pKa of 1.99