Chapter U2, Problem C9.1E

Interpretation Introduction

Interpretation : The method of determining if two molecular models are mirror image isomers or not is to be explained.

Concept Introduction : In nature one comes across many things that are mirror images of each other. For example: our hands, ears and eyes. These body parts look similar in their structure but are different as one cannot superimpose them on each other. Mirror image isomers are molecules that have the same molecular formula and structural formula but different spatial arrangement of atoms.

Answer to Problem C9.1E

If two molecules are mirror image of each other and cannot be superimposed on each other, they will form mirror image isomers. For a molecule to have mirror image isomer, it should have a carbon atom that is attached to four different groups.

Explanation of Solution

Mirror image isomers are molecules that have the same molecular formula and structural formula but different smells. They are mirror image of each other and cannot be superimposed on each other.

Limonene, C₁₀H₁₆ has a mirror image isomer. The two isomers are different molecules as one cannot be superimposed on the other molecule. One can say that one molecule is left handed and other molecule is right handed. They are isomers of each other.

For a molecule to have mirror image isomer, it should have a carbon atom that is attached to four different groups. Example: chlorofluoromethanol, CHClFOH. In this molecule, the carbon atom is attached to four different groups; a hydrogen, a hydroxyl group, a chlorine atom and a fluorine atom. Such molecules have mirror image isomers that cannot be superimposed on one another.

Conclusion

If the two isomers cannot be superimposed on each other, they are mirror- image isomers. If a molecule has a carbon atom attached to four different group of atoms, it can form a mirror image isomer.