Please provide the structures of the compounds for question 4 so I can explain how to distinguish them.

The compounds to be distinguished in question 4 are not visible in the provided image. Please provide the structures of the compounds you would like me to explain how to distinguish.

However, I can explain the general approach to answering such a question:

General Approach to Distinguishing Compounds:

To distinguish between two organic compounds, you typically look for differences in their functional groups. Different functional groups react in characteristic ways with specific reagents, leading to observable changes.

Steps:

1. Identify the functional groups present in each compound.
2. Look for a difference in the functional groups that can be exploited by a specific chemical test.
3. Choose a suitable reagent that reacts with one functional group but not the other (or reacts differently).
4. Describe the expected observation for each compound with the chosen reagent.

Examples of common distinguishing tests (if the compounds were provided):

• To distinguish an alkene from an alkane:

  • Reagent: Bromine water ($\text{Br}_2$ in $\text{H}_2\text{O}$)
  • Observation: The alkene would decolorize the reddish-brown bromine water due to addition across the double bond. The alkane would show no reaction (the bromine water would remain reddish-brown).

• To distinguish an aldehyde from a ketone:

  • Reagent: Tollens' reagent (ammoniacal silver nitrate solution)
  • Observation: The aldehyde would form a silver mirror on the walls of the test tube. The ketone would show no reaction.

• To distinguish a carboxylic acid from an alcohol or phenol:

  • Reagent: Sodium bicarbonate ($\text{NaHCO}_3$) solution
  • Observation: The carboxylic acid would react to produce effervescence (bubbles of $\text{CO}_2$ gas). The alcohol or phenol would show no reaction.