Organic- Aldehydes & Ketones Flashcards
Why do aldehydes and ketones have lower boiling points than alcohols with the same number of carbon atoms?
There is hydrogen bonding between the alcohol molecules. This is a stronger intermolecular force than the dipole dipole attractions between the carbonyl compounds
What is the nucleophile produced by NaBH4 and LiAlH4?
Hydride ion ( H minus )
What is a suitable reducing agent for the reduction of a carbonyl compound to an alcohol?
Lithium tetrahyridoaluminate and sodium teranydridoborate
What are the conditions for the nucleophilic addition of cyanide ions to aldehydes or ketone?
Reflux in alkaline solution
Why do aldehydes and ketones have higher boiling points than alkanes with the same number of carbon atoms?
The carbonyl bond means that there are permanent dipole dipole interactions between the molecules which are not present between the alkane molecule
What is the difference in structure between an aldehyde and ketone?
Aldehydes - have at least one H attached to the carbonyl group
Ketones- have two carbons attached to the carbonyl group
Why are small carbonyl compounds miscible in water?
The formation of hydrogen bonds from the water to the oxygen of the carbonyl compound.
How can ketones be formed?
Oxidation of a secondary alcohol
How can aldehydes and ketones be distinguished?
Fehling’s solution or Tollens reagent
How can aldehydes be formed?
Oxidation of a primary alcohol or reduction of a carboxylic acid.
What is the name of the mechanism for the reduction of carbonyls?
Nucleophilic addition
Under which conditions are hydroxynitriles formed?
Addition of KCN followed by dilute acid to a carbonyl
Why is the carbonyl bond polar?
The difference in electronegativity between carbon and oxygen
What hazards are associated with using KCN?
It is highly toxic
What is the reagent and conditions for the reduction of carbonyl compounds?
NaBH4 and solution is aqueous
