Organic Chemistry - carbonyl compounds

Question 1

what are carbonyl compounds?

Answer 1

molecules that contain carbonyl functional groups, C = O

Question 2

aldehydes

Answer 2

attach to one carbon atom, they have functional group C = O

Question 3

ketone

Answer 3

attach to two carbon atoms, they have functional group C = O

Question 4

simple test for aldehydes and ketones

Answer 4

aldehydes will react with oxygen and form carbonxylic acid, but ketone wouldn’t

Question 5

tollens’ reagent

Answer 5

of Ag(NH3)2+ — colourless solution dissolved in aqueous ammonia. if it’s heated in a test tube with an aldehyde, a silver mirror forms after a few minutes.

aldehydes and ketones are flammable, so they must be heated in a water bath rather than over a flame

Question 6

fehling’s solution

Answer 6

is a blue solution of complexed copper(ll) ions dissolved in sodium hydroxide. if it’s heated with an adehyde, the solution will become a brick red ppt of

Question 7

hydroxynitriles

Answer 7

molecules which contain a hydroxyl group (OH) and a nitrile group (CN)

Question 8

the _____ group is the most important

Answer 8

nitrile

Question 9

carboxylate salts

Answer 9

sodium methanoate

sodium butanoate

Question 10

acyl chlorides

Answer 10

Acid chlorides are named using the suffix: –anoyl chloride

propanoyl chloride
ethanoyl chloride

The group is always at the end of the molecule, so numbering is not necessary.

Question 11

acid anhydrides

Answer 11

If both alkyl groups are the same, acid anhydrides are named using the suffix –anoic anhydride

Eg
ethanoic anhydride

If the alkyl groups are different, each must be specified:

Eg
methanoic ethanoic anhydride

Question 12

amides

Answer 12

Amides are named using the suffix –anamide

Eg
propanamide
methanamide

The group is always at the end of the molecule, so numbering is not necessary.

Question 13

esters

Answer 13

Esters are named using an alkyl prefix to indicate the group attached to the single O and the suffix –anoate to indicate the group attached to both oxygen atoms.

Eg
methyl methanoate

The methyl indicates the number of carbons in the chain attached to the single O (ie 1), and the methanoate indicates the number of carbons in the chain attached to both O atoms

propyl ethanoate

Question 14

N-substituted amides

Answer 14

N-substituted amides are named using an N-alkyl prefix to indicate the group attached to the N only and the suffix –anamide to indicate the group attached to both O and N atoms.

Eg
N-ethyl ethanamide

The ethyl indicates the number of carbons in the chain attached to the N only (ie 2) and the ethanamide indicates the number of carbons in the chain attached to both N and O (ie 2)

N-methyl propanamide

Question 15

amines

Answer 15

Primary amines are named using the prefix amino- followed by the suffix –ane.

If the carbon chain contains more than 2 carbon atoms, the amino should be preceded by a number to indicate the position of the amino group on the chain.

Eg
aminomethane

2-aminopropane

Secondary amines are named by using a N-alkyl prefix to indicate the nature of the shorter chain attached to the N atom. The longest chain is named afterwards, followed by the suffix –ane.

Eg
N-methylaminoethane

N-methyl, 2-aminopropane

Tertiary amines are named in the same way as secondary amines. The two shortest alkyl groups are indicated with a N-alkyl prefix.

Eg
N-methyl, N-ethylaminoethane

N-methyl, N-ethyl, 1-aminopropane

Question 16

NOMENCLATURE OF COMPOUNDS CONTAINING MORE THAN ONE FUNCTIONAL GROUP

Answer 16

• If one of the functional groups is an amine or a haloalkane, the molecule is named simply by adding the necessary prefix:
• If one of the functional groups is an alcohol and the other is a nitrile or anything containing a C=O bond, the alcohol group is named using a hydroxy- prefix.
• If one of the functional groups is an alcohol and the other is anything other than an amine or a haloalkane, the molecule is named by replacing the –an- part of the name with –en-, including a number if the position of the alkene has to be specified.