How many atoms in the pictured molecule can form hydrogen bonds with water molecules?

Question

A ball-and-stick model of a molecule. The structure of the molecule, described from left to right, is four atoms attached to each other: one nitrogen, two carbons, and one oxygen. There are two hydrogen atoms attached to each nitrogen and carbons. There is one hydrogen atom attached to the oxygen atom.

3
8
7
2
5

Answer 1

To determine how many atoms in the described molecule can form hydrogen bonds with water molecules, we need to identify the functional groups present and the specific atoms involved.

From your description:

• There is one nitrogen (N) atom with two hydrogen (H) atoms attached to it (NH2 group).
• There are two carbon (C) atoms; typically, C does not form hydrogen bonds directly in biological contexts.
• There is one oxygen (O) atom with one hydrogen (H) atom attached to it (OH group).

In terms of hydrogen bonding:

• The nitrogen atom (NH2) can act as a hydrogen bond donor since it has two hydrogen atoms that can interact with electronegative atoms like oxygen in water.
• The oxygen atom (OH) can participate as both a hydrogen bond donor (due to the hydrogen atom) and a hydrogen bond acceptor (due to the lone pairs on oxygen).

So let's summarize:

1. Nitrogen (N) - has 2 hydrogen atoms that can participate in hydrogen bonding.
2. Oxygen (O) - has 1 hydrogen atom that can participate in hydrogen bonding as well.

Adding them up:

• Nitrogen contributes 2 hydrogen atoms.
• Oxygen contributes 1 hydrogen atom.

Therefore, a total of 3 atoms (2 from nitrogen and 1 from oxygen) can form hydrogen bonds with water molecules.

The answer is 3.