Chapter 15, Problem 82A

Interpretation Introduction

Interpretation: To show the hydrogen bonding of the water molecule with other water molecules.

Concept Introduction: In the water molecule, the oxygen and hydrogen atoms are held together by strong covalent bonding that is formed by the sharing of an electron pair. However, the electrons in this bond are not shared equally. One atom in a covalent bond often has a greater tendency to attract to the shared pair of electrons than the other atom. This tendency is known as electronegativity.

Answer to Problem 82A

The hydrogen bonding between water molecules is shown below.

Explanation of Solution

Oxygen is more electronegative than hydrogen, so it has a stronger pull on the pair of electrons than the hydrogen atom. This results in the formation of a polar bond due to unequal sharing. The hydrogen atom at one end of the bond carries a partial positive charge $\left(\delta +\right)$ , while the oxygen atom at the other end has a partial negative charge $\left(\delta -\right)$ .

The arrangement of water molecules relative to one another is shown below:

The oxygen end is an electrically negative region that has more electronegativity than the hydrogen atoms, which carry a partial positive charge $\left(\delta +\right)$ . The electronegativity difference between hydrogen and oxygen, along with the bent shape of the water molecule, results in a quite polar molecule.

  

Conclusion

The hydrogen bonding existing between water molecules is held by intermolecular forces.