To produce a pure sample of solute A, which is soluble in hexane, you can use the principle of liquid-liquid extraction. Here are the practical steps involved:
Materials needed:
1. Aqueous solution containing solutes A and B
2. Hexane
3. Separatory funnel (a bottle-shaped glassware with a stopcock at the bottom)
4. Beaker or conical flask
5. Filter paper or funnel
6. Glass stirring rod or vortex mixer
Procedure:
1. Start by setting up your equipment in a suitable work area, ensuring proper ventilation.
2. Pour the given aqueous solution containing solutes A and B into a beaker or conical flask.
3. Add an equal volume of hexane to the aqueous solution. Since hexane is immiscible with water, it will form a separate layer on top.
4. Use the stirring rod or vortex mixer to thoroughly mix the two layers, ensuring that solute A gets distributed between the aqueous and hexane layers.
5. After mixing, allow the two layers to separate naturally. This is where the separatory funnel comes into play.
6. Place the separatory funnel into a ring stand, making sure the stopcock is closed.
7. Carefully transfer the mixture from the beaker or conical flask into the separatory funnel, taking care not to mix the layers.
8. Wait for the layers to separate strictly based on density. The denser layer (in this case, the aqueous layer with solute B) will settle at the bottom, while the hexane layer with solute A will be on top.
9. Once the layers have settled, open the stopcock and allow the lower aqueous layer to slowly drain into a waste container. Be careful not to let any of the hexane layer or solute A go through the stopcock.
10. Close the stopcock once only hexane is left in the separatory funnel.
11. Repeat steps 6 to 10 for a second extraction, which helps ensure separation and purification of solute A.
12. Finally, transfer the hexane layer containing solute A from the separatory funnel into another container, such as a beaker or conical flask.
13. To separate any remaining impurities, filter the hexane solution containing solute A using filter paper or a funnel into a clean container.
14. Leave the container of filtered hexane solution in a well-ventilated area to allow any remaining hexane to evaporate, leaving behind a pure sample of solute A.
By following these steps, you can obtain a pure sample of solute A from the aqueous solution.