Chapter 4, Problem 4.1P

Interpretation Introduction

Interpretation:

The two factors behind the polar nature of water are to be determined.

Concept introduction:

A solution is a combination of two parts: solute and solvent. The solute is the substance that is present in small quantity and solvent is the substance in which solute is dissolved. Water is considered as one of the active solvents.

A polar molecule is a molecule in which there is an unequal distribution of electron density between the bonds present in the molecule. A polar molecule has partial charges on the atoms of the molecule. The general representation of the polar molecule is:

Here, B is more electronegative than A.

Answer to Problem 4.1P

The two factors behind the polar nature of water are:

1. Unequal distribution of electrons in the $\text{O}-\text{H}$ bond.

2. Bent structure of water molecule.

Explanation of Solution

A water molecule has a bent structure with oxygen atom present as central atom and hydrogen atoms are present as side atom. The structure of the water molecule is,

In the $\text{O}-\text{H}$ bond of the water molecule, the oxygen atom is more electronegative as compared to a hydrogen atom. Therefore the oxygen atom will attract the bonding electrons more towards itself and become partially negative charged and hydrogen becomes partially positive charged. This unequal distribution of bonding electrons in the $\text{O}-\text{H}$ bond makes the water molecule polar in nature.

Conclusion

Unequal distribution of electrons in the $\text{O}-\text{H}$ bond and bent structure of water molecule makes the water molecule polar in nature. Due to the more negative nature of oxygen atom, the oxygen atom will attract the bonding electrons more towards itself and become partially negative charged and hydrogen becomes partially positive charged.