Topic 17: Carboxylic Acids Flashcards
What is the carboxylic acid functional group?
-C=OOH
Do carboxylic have high or low melting and boiling points? Explain:
Relatively high:
- the intermolecular forces that carboxylic acids experience are high due to the polarised C=O and O-H groups
Can carboxylic acids form hydrogen bonds?
Yes - due to the OH bond
Explain the trend in solubility of the carboxylic acids
However, solubility falls as the length of the hydrocarbon chain in the carboxylic acid increases
The hydrocarbon chains are forcing their way between water molecules and so breaking hydrogen bonds between those water molecules
Carboxylic acids with more than eight carbon atoms will be solids at room temperature and are very slightly soluble in cold water, but will be more soluble in hot water
How can a carboxylic acid be formed from alcohols?
oxidation of primary alcohols and aldehydes by either acidified K2Cr2O7 or acidified KMnO4 and reflux
How can a carboxylic acid be formed from the hydrolysis of nitriles?
Hydrolysis of nitriles using either dilute acid or dilute alkali followed by acidification
Hydrolysis by dilute acid results in the formation of a carboxylic acid and ammonium salt
What is the reaction with LiAlH4?
Reduction to a primary alcohol
Conditions: Dry ether and room temperature
How do you destroy any extra LiAlH4?
Addition of water at the end of the reaction
What is the reaction with a base?
Forms a salt:
