Chapter 23, Problem 9STP

Interpretation Introduction

Interpretation : To write the structural formula and the name of each compound with the molecular formula ${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}\text{O}$

Concept Introduction: Structural Formula will give a brief picture of atoms or molecules in the order they are bonded. It also represents how the atoms are bonded to one another via a single bond, double bond, or triple bond. In the structural formula, the covalent bonds are represented by a dash. The IUPAC name is given according to the rules which state that the aldehyde should have the suffix ‘al’ and the ketone should have the suffix ‘one’

Answer to Problem 9STP

The two carbonyl compounds are propanone and Propan-1-al

  

  

Explanation of Solution

Propan-1-al and propanone belong to the carbonyl compounds. In propan-1-al the functional group is aldehyde and in propanone the functional group is ketone. The longest chain in both the compounds is three carbon chain hence, it will be named ‘Propane’ according to IUPAC. Since the suffix for ketone is ‘one’ the ‘e’ from the propane will be excluded and it will be named propanone. Similarly in the case, of aldehyde the suffix is ‘al’ the ‘e’ from the propane will be excluded and will be named as Propan-1-al. 1 is the position of the aldehyde group.

Conclusion

Aldehydes and ketones can also be distinguished by their position. Aldehydes are present at the end of the carbon chain and ketones are present in between the alkyl chain. This plays a key role in considering the structure of a compound as aldehyde and ketone which helps in determining structural formula.