Term
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Definition
| 2 carboxyl groups on one benzene ring |
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Term
| What is the hybridization of the C's and O's in Carboxyl groups? |
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Definition
sp2 for both, because ressonance causes the O that would appear to be sp3 to form a double bond meaning that sp2 takes presidence. |
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Term
boiling point relative to similar alcohols? |
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Definition
| much higher due to dimer formation |
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Term
| Which acids are solid at room temperature? |
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Definition
Aliphatic acids of 8 carbons or more |
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Term
| What do double bonds do to the melting point of acids? |
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Definition
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Term
| Explain the solubility of Carboxilic acids |
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Definition
| Solubility in water decreases with chain length, up to 4 carbons in the acid is still soluble in water. They are more soluble in alcohol, and more soluble in non-polar solvents that break up the dimer. |
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Term
How do substituents affect acidity? |
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Definition
The more subsituents the more acidic the chain. On a benzene: Activating in para<none<Deactivating in meta<deactivating in para<deactivating in ortho. |
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Term
How does one convert the carboxylic acid to a salt? How does one remake the acid from the salt? |
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Definition
| Add sodium hydroxide to make it a salt, and a strong acid like HCl will return it to an acid. |
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Term
| What are some of the properties of acidic salts? |
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Definition
| Solid with no real smell, and soluble in water if made with Na, K, Li, or NH4. |
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Term
| Formation of salt from an acid combined with NaHCO3 releases what? |
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Definition
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Term
| What are the products formed from hydrolysis of a fat? |
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Definition
| A glycerol and fatty acid salts |
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Term
What are some identifying characteristics of a Carboxylic acid under UV Spectroscopy? |
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Definition
| Saturated carboxylic acids have a weak absorbtion around 200-215 nm. if C=C isconjugated with C=O, the molar absorptivity is 10,000 at 200nm. An additional conjugated double bond increases the absorption to a wavelength of 250nm. |
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Term
| Why is the maximum value in Mass spectroscopy almost never observed? |
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Definition
| because the molecule rearranges quickly |
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Term
| What are the main ways to synthesize carboxylic acids? (4) |
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Definition
1. Oxidation of primary alcohols and aldehydes using chromic acid or KMnO4 (makes an aldehyde first, and then forms a carboxylic acid). 2. an alkene with KMnO4 at high temperatures cleaves the double bond, forming a carboxylic acid if one C has an H on it. 3. Cleavage of an alkyne with ozone or hot permanganate. 4. Alkyl benzenes oxidized to Benzoic acid by Hot KMnO4 or hot chromic acid |
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Term
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Definition
Carboxylate salt (addition of a strong acid to form carboxylic acid) |
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Term
How does one form a carboxylic acid from a nitrile? |
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Definition
| by basic or acidic Hydrolysis |
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Term
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Definition
| A compound where there is an oxygen between 2 carbonyl groups. |
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Term
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Definition
| ester+H20 (fischer esterification) |
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Term
| How is fischer esterification catalyzed? |
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Definition
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Term
| What is a potentially unwanted quality of Fishcher esterification? How is it avoided? |
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Definition
All the steps are reversible, meaning it reaches an equillibrium. It can be avoided by removing the water as it forms. |
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Term
Explain the mechanism for fischer esterification? |
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Definition
1. Protonation of carbonyl and attack of an alcohol on the carbon (another alcohol takes the extra H) 2. Protonation of OH and loss of water, yielding the ester. |
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Term
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Definition
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Term
| How does Diazomethane react with Carboxylic acids? |
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Definition
| it produces methyl esters quantitative conversion, meaning no equilibrium. (gives off nitrogen gas) |
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Term
How does an amine (base) react with carboxyilc acid? |
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Definition
| It removes a proton to form a salt, and heating the salt above 100 C drives off steam and forms an amide. |
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Term
Acid+LiAlH4 (followed by H20)=? |
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Definition
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Term
| What must be done to an acid in order to create an aldehyde? What happens otherwise? |
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Definition
| The acid must be made more reactive (Ex, change it to an acid chloride) and be reduced with a weaker reducing agent (ex. LiAl[OC(CH3)3]3H) to yield an aldehyde. Otherwise the reaction keeps going beyond an aldehyde |
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Term
| How do you form a Ketone from acids? |
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Definition
| By reacting 2 equivalents of an organolithium reagent with the acid. |
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Term
| How does one synthesis and acid chloride? |
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Definition
| by using thionyl chloride(SOCl2) or oxalyl chloride (C2O2Cl2) |
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Term
| Acid Chlorides + Alcohol=? |
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Definition
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Term
| How does one form an amide from acid chlorides? |
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Definition
| By addition of ammonia (a base can be added to remove the HCl byproduct) |
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