CHM105: Chapter 14

What functional group do aldehydes and ketones have in common?

Carbonyl group (C=O)

How is the carbonyl group in an aldehyde bonded?

To at least one hydrogen atom

What is the general formula notation for an aldehyde?

-CHO

Ketones have the carbonyl group bonded to ____________.

two carbon groups

The polarity of the carbonyl group arises because:

Oxygen is more electronegative than carbon.

In the IUPAC system, how are aldehydes named?

By replacing the -e in the alkane name with -al.

Why do aldehydes not require a number for the carbonyl position in their IUPAC names?

The carbonyl group is always at the end of the chain.

What is the common name for propanone?

Dimethyl ketone.

How are ketones named using the IUPAC system?

By replacing the -e in the alkane name with -one.

How is a cyclic ketone named?

By using the prefix 'cyclo-' before the ketone name.

What happens to the boiling points of aldehydes and ketones as the number of carbon atoms increases?

Boiling points increase.

Which compound has the highest boiling point?

Alcohol.

Why do aldehydes and ketones have higher boiling points than alkanes?

They have dipole-dipole interactions.

Why do ketones have lower boiling points than alcohols of similar mass?

Alcohols form hydrogen bonds, while ketones do not.

Aldehydes and ketones are soluble in water if they:

Have one to four carbon atoms.

What happens when aldehydes are oxidized?

They form carboxylic acids.

Which test is used to distinguish aldehydes from ketones?

Tollens’ test.

What does a positive Tollens’ test indicate?

The presence of an aldehyde.

What is observed in a positive Tollens’ test?

Formation of a silver mirror.

Benedict’s test detects:

Aldehydes with an adjacent hydroxyl group.

What is the reducing agent in the reduction of aldehydes and ketones?

H₂

What is the product of the reduction of an aldehyde?

Primary alcohol.

What is the product of the reduction of a ketone?

Secondary alcohol.

A hemiacetal contains which two functional groups?

Hydroxyl (-OH) and alkoxy (-OR).

What is required to convert a hemiacetal into an acetal?

Addition of another alcohol molecule.

Why are ketones less reactive than aldehydes?

Ketones have two alkyl groups that reduce the carbonyl’s reactivity.

What type of structure does glucose form in solution?

Cyclic hemiacetal.

What happens when an alcohol adds to a cyclic hemiacetal?

It forms a cyclic acetal.

Acetals are commonly used in:

Vitamins, dyes, pharmaceuticals, and perfumes.

The reaction forming hemiacetals and acetals is:

Reversible.