Chapter 23, Problem 49A

Interpretation Introduction

Interpretation: To distinguish the polarity of the carbon-carbon double bond and a carbon-oxygen double bond.

Concept Introduction: The polarity of the atoms that are bonded together will depend on the electronegativity of the two atoms. If one of the atoms is more electronegative than the other atom electrons of the bond will move towards the atom with more electronegativity and will result in partial negative and positive charge. If both the atoms have similar electronegativity then there is no polarity as there is no movement of electrons and hence no charge will be developed.

Answer to Problem 49A

In a carbon-carbon double bond, the electronegativity of both carbons is the same therefore, there is no polarity. In the carbon-oxygen double bond, the electronegativity of oxygen is more than that of the carbon therefore, the bond is polar.

Explanation of Solution

When a carbon-carbon double bond is considered the electronegativity of both carbons are same. Due to this, there will be no charge distribution on both carbons. Therefore, the carbon-carbon bond will be non-polar. Whereas, in the case of the carbon-oxygen double bond oxygen is more electronegative than carbon. Due to this, there is a charge developed on both carbon and oxygen. The oxygen will gain a partial negative charge and the carbon will gain a partial positive charge that results in polarity.

Conclusion

If one of the atoms is more electronegative then that atom will gain the electron and become electron-rich and gains the partial negative charge. Since the other atom is less electronegative it will lose electrons and gain partial positive charge.