Study the reaction scheme and answer the questions that follow - Leaving Cert Chemistry - Question 8 - 2012

Structural isomers are compounds that have the same molecular formula but differ in the arrangement of atoms, resulting in different structural formulas. In this case, alcohol A (propan-2-ol) and propan-1-ol both have the formula C3H8O but differ in the position of the hydroxyl (–OH) group.

A primary alcohol has the hydroxyl (-OH) group attached to a carbon atom that is connected to only one other carbon (e.g., in propan-1-ol), while a secondary alcohol has the hydroxyl group attached to a carbon atom that is bonded to two other carbons (e.g., in propan-2-ol).

Another pair of structural isomers from the reaction scheme is propanal and propanone, which differ in the placement of the carbonyl (C=O) group.

In the reaction scheme, the compound propan-2-ol has a carbon atom in tetrahedral geometry due to the presence of four substituents around it.

The reagent used for the conversions labelled R is hydrogen, and the catalyst can be nickel, palladium, or platinum.

The oxidation of propyl alcohol using Fehling's reagent involves mixing Fehling's solution A and B, heating the mixture, and adding the alcohol to be oxidised. The solution will turn from blue to a brick-red precipitate of copper(I) oxide (Cu2O) as the alcohol is oxidised.

Propanone does not react with Fehling's reagent because it is a ketone, and ketones are typically not easily oxidised by Fehling's reagent, which is a reducing agent.

The compound expected to have a fruity odour is the ester B, propyl methanoate, which is known for its characteristic scent similar to fruits.