Aldehyde and ketone

Question 1

What are Aldehydes

Answer 1

In aldehydes, the carbonyl group has one hydrogen atom attached to it together with either a 2nd
hydrogen atom or a hydrogen group which may be an alkyl group or one containing a benzene ring.

Question 2

What are Ketones

Answer 2

In ketones, the carbonyl group has 2 hydrocarbon groups attached to it. These can be either the ones containing benzene rings or alkyl groups. Ketone does not have a hydrogen atom attached to
the carbonyl group

Question 3

Aldehydes and ketones are organic compounds which incorporate

Answer 3

a carbonyl functional group, C=O

Question 4

If at least one of these substituents is hydrogen, the compound is

Answer 4

an aldehyde

Question 5

If neither is hydrogen, the compound is

Answer 5

a ketone

Question 6

Combined with other functional group aldehydes and ketone are widespread in nature. Compounds such as

Answer 6

cinnamaldehyde (cinnamon bark), vanillin (vanilla bean), Citra (lemongrass),, and camphor (camphor trees)
are found chiefly in microorganisms or plants.

Whereas, compounds such as testosterone (male sex hormone), and progesterone (female sex hormone), cortisone (adrenal hormone) have animal and human origin.

Question 7

The C=C of alkenes has an average bond energy of

Answer 7

146 kcal/mole

Question 8

Since a C–C σ- bond has a bond energy of

Answer 8

83 kcal/mole

Question 9

the π-bond energy may be estimated at

Answer 9

63 kcal/mole

Question 10

is the simplest aldehyde

Answer 10

Formaldehyde

Question 11

is the smallest ketone

Answer 11

acetone

Question 12

Uses of Aldehydes

Answer 12

 Formaldehyde is a gas. With 40% solution in water, it forms Formalin which
is used in preserving biological specimens.

 Formaldehyde is used in embalming, tanning, preparing glues and polymeric products, as germicides, insecticides, and fungicides for plants. It is also used in drug testing and photography.

 When reacted with phenol, formaldehyde forms Bakelite, which is used in plastics, coatings, and adhesives.

 Acetaldehyde is largely used for the production of acetic acid and pyridine derivatives.

 Benzaldehyde is used in perfumes, cosmetic products, and dyes. It is added to provide almond flavour to food products and also used as a bee repellent.