Question

Which functional group is not present in this molecule?

1. carboxyl

2. sulfhydryl

3. hydroxyl

4. amino

Short answer

1. The option “carboxyl” isfalse.

2. The option “sulfhydryl” istrue.

3. The option “hydroxyl” is false.

4. The option “amino” is false.

Step-by-step solution

Explanation of option (A)

A carboxyl group is a functional group that comprises two functional groups, hydroxyl (OH) and carbonyl (=O), attached to a single carbon atom. The carbon atom is double-bonded to an oxygen atom and singly linked to a hydroxyl group in this group.

In the given molecule, one carboxyl group is present.

Therefore, the given option is false.

Explanation of option (B)

A sulphydryl group (-SH) is also called the thiol group. It is a functional group made up of a sulfur atom connected to hydrogen by two lone pairs.It is usually found as disulfide bonds in their oxidized form.

In the given molecule, the sulfhydryl group is absent.

Therefore, the given option is true.

Explanation of option (C)

A hydroxyl group (OH) is a functional group made up of an oxygen atom connected to a hydrogen atom by two lone pairs. The addition of a hydroxyl group to many organic compounds converts them to alcohols, which increases their water solubility.

In the given molecule, two hydroxyl groups are present.

Therefore, the given option is false.

Explanation of option (D)

An amino (NH2) is a functional group made up of one nitrogen atom connected to two hydrogen atoms. In organic compounds, the amino group is one of the numerous nitrogen-containing functional groups.

In the given molecule, one amino group is present.

Therefore, the given option is false.