Chapter 18, Problem 9TE

Why don’t the dipoles of the two hydrogen-oxygen bonds in a water molecule cancel each other out?

To determine

The reasin that the dipoles of two hydrogen-oxygen bonds do not cancel each other in a water molecule.

Answer to Problem 9TE

The dipoles of two hydrogen-oxygen bonds in a water molecule are not equal and opposite and thus cannot cancel out each other.

Explanation of Solution

The dipole is a charge separation of a covalent molecule. The sharing of electrons between the atoms with a slight electronegativity difference creates a dipole and generates a polar covalent molecule. In a dipole bond, the atom with slightly higher electronegativity try to attract electrons more towards it and gain a partial negative charge while the other element present with slightly lesser electronegativity gains a partial positive charge.

A water molecule is basically a covalent as well as polar molecule with two hydrogen-oxygen polar bond. The structure of water molecule is tetrahedral and the bonds are not placed in equal as well as opposite direction. Thus, due to this, the dipoles cannot cancel each other instead give the collective dipole value of the hydrogen-oxygen polar bond.

Conclusion:

Therefore, the dipoles of two hydrogen-oxygen bonds in a water molecule are not equal and not opposite and thus cannot cancel out each other.