Question

Describe how the process of distillation could be used to separate a solution into its component substances. Give an example.

Short answer

Distillation is a method used to separate components of a solution with different boiling points. For example, in a solution of water and ethanol, you would set up a distillation apparatus, gradually heat the solution to \(78^{\circ}\)C, ethanol's boiling point, causing it to vaporize, travel through a cooled condenser, and then collect in a separate container. Repeat the process with water's boiling point of \(100^{\circ}\)C to collect the water component. After the process, you will have two containers: one containing ethanol and the other containing water.

Step-by-step solution

Understand the basic concept of distillation

Distillation is a method used to separate a solution containing multiple substances, typically liquids, with different boiling points. The process involves heating the solution until one of the components vaporizes, then cooling the vapor back into a liquid for collection.

Identify the substances in the solution

In order to perform distillation, one must first identify the substances present in the solution, their boiling points, and their miscibility. This information will help in setting the right temperature for effective separation. For example, a common solution to separate via distillation is a mixture of water and ethanol (alcohol).

Set up the distillation apparatus

Set up the distillation apparatus by assembling the following components: a heat source, a round-bottom flask to hold the solution, a condenser, and a collection container for the separated liquid. The round-bottom flask should be connected to the condenser, which is then connected to the collection container. Ensure that all connections are airtight to avoid any loss of vapor during the process.

Heat the solution

Place the solution in the round-bottom flask and start heating it. Ensure that the heat is properly adjusted to be gentle and uniform across the liquid. Gradually increase the temperature until it reaches the boiling point of the substance with the lowest boiling point (e.g., ethanol has a boiling point of \(78^{\circ}\)C, while water has a boiling point of \(100^{\circ}\)C).

Separating the substances

As the temperature reaches the boiling point of the first substance, it will vaporize and travel through the connected tubes into the condenser. The condenser, which is cooled by running cold water, will cause the vapor to lose energy and condense back into a liquid. This separated liquid then collects in the collection container.

Complete the distillation and analyze the collected substances

Continue the process until the round-bottom flask no longer contains the substance with the lower boiling point. The collected liquid in the container will be the first substance isolated from the solution (e.g., ethanol). Next, increase the temperature to the boiling point of the remaining substance (e.g., water) and repeat steps 4 and 5 to collect it in a separate container.

Example: Separating water and ethanol

To separate a solution of water and ethanol, set up the distillation apparatus as described in step 3. Heat the solution gradually until the temperature reaches \(78^{\circ}\)C, the boiling point of ethanol. The ethanol will vaporize, pass through the condenser, and collect in a container. After all the ethanol has been collected, increase the temperature to \(100^{\circ}\)C to separate and collect the water. At the end of the process, you will have two containers: one containing ethanol and the other containing water.