Q9.54P - Chemistry: Molecular Nature Of Matter And Change

Question

Is the H-O bond in water nonpolar covalent, polar-covalent, or ionic? Define each term, and explain your choice. 

Step-by-Step Solution

Answer

A water molecule contains polar-covalent bonding.

 

In nonpolar covalent bonding, there is only sharing of electrons, no difference in electronegativity between the two atoms forming the bond.

In polar-covalent bonding, the electronegativity difference between the two atoms is huge (above 1.7).

In ionic bonding, the electronegativity difference between the two atoms is small.

In the case of water molecules, the electronegativity difference between H-atom (2.1) and an O-atom (3.5) is 1.4, therefore they form polar-covalent bonding.

 

Step 1: Definition

A covalent bond can be formed by the sharing of the valence electron of an atom and is quite a strong bond.

 

Polar-covalent bond can be defined as the molecule formed by the sharing of the electron by still can form ions.

 

Ionic bond can be defined as the force of attraction in which both opposites charged attract each other. It is also a strong bond the greater the value of ions, the greater the force of attraction.

Step 2: Explanation.

• A water molecule has polar-covalent bonding.
• The water molecule contains H-atom having one electron in the valence shell and an O-atom having six electrons in the valence shell forming a covalent bond by sharing electrons.
• The molecule can also dissociate into  ${\mathbf{H}}^{+}$  and  ${\mathbf{OH}}^{\mathbf{-}}$  ions by using electricity.
• Due to the formation of the covalent and polar bonds, it forms a strong bond.
• The water molecule can exist in all three phases due to this special bonding- Solid, Liquid, and gaseous.

• Here, the electronegativity difference between H-atom (2.1) and an O-atom (3.5) is 1.4, therefore they form polar-covalent bonding.