Chapter 18, Problem 12TE

If water were linear like carbon dioxide, would it be polar or nonpolar? Would its boiling point be higher or lower than $100\text{C}$?

To determine

Whether water would have been polar or nonpolar if it was linear and whether the boiling point of it would have been lower or higher than $100\text{C}$.

Answer to Problem 12TE

If water were linear like carbon dioxide it would become nonpolar as the equal and opposite dipoles get cancelled out each other and the boiling point will be lower than $100\text{C}$.

Explanation of Solution

The oxygen atom is a central atom making two covalent bonds with the hydrogen atoms. A water molecule is a polar covalent molecule with two hydrogen-oxygen polar bonds. The oxygen atom contains six electrons in its existing outermost shell or a valence shell. Among those six electrons, two electrons are involved in the mutual sharing of two electrons to form two hydrogen-oxygen covalent bonds of a water molecule and the remaining four electrons make the nonbonding pairs of electrons.

If a water molecule is made linear the dipole of the opposite bonds will cancel out each other and will make the water molecule a nonpolar molecule. Thus due to this non-polarity of a molecule the physical properties like the boiling point of water molecule will reduce.

Therefore, if water molecule was linear like carbon dioxide molecule it would become nonpolar as the equal and opposite dipoles cancel out each other and the boiling point will be lower than $100\text{C}$.

Conclusion:

Thus, if water were linear like carbon dioxide it would become nonpolar as the equal and opposite dipoles get cancelled out each other and the boiling point will be lower than $100\text{C}$.