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.

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 atoms that can participate in hydrogen bonding.

1. Atoms in the molecule:

   • Nitrogen (N) with 2 hydrogen atoms (N-H)
   • Carbon (C) with 2 hydrogen atoms each (C-H)
   • Oxygen (O) with 1 hydrogen atom (O-H)

2. Hydrogen bonding criteria: For hydrogen bonds to form, a hydrogen atom must be attached to a highly electronegative atom (like N or O) that can interact with the electronegative atoms in water (which are also N or O).

3. Identifying atoms that can participate:

   • The nitrogen atom has 2 hydrogen atoms attached to it (N-H), which can participate in hydrogen bonding with water.
   • The oxygen atom has 1 hydrogen atom attached to it (O-H), which can also participate in hydrogen bonding.
   • The carbon atoms are not typically involved in hydrogen bonding since they are less electronegative and do not have hydrogen atoms connected to them that can engage in this type of bonding.

Summing these up:

• 2 hydrogen atoms from nitrogen can form hydrogen bonds.
• 1 hydrogen atom from oxygen can form a hydrogen bond.

Thus, the total number of atoms that can engage in hydrogen bonding with water is 3. However, no options provided match this count.

If we strictly consider the atoms themselves that facilitate hydrogen bonds (the nitrogen and oxygen), then 2 (N and O) are the key atoms.

The closest fit from the choices you provided would be 2, based on the number of atoms (N and O) that can form hydrogen bonds directly.