Isolation of Caffeine from Teabags
Purpose:
The purpose of the lab is to separate caffeine from the teabags by using three techniques, extraction, recrystallization, and melting point determination.
Procedure:
1. In the first step we have to brew a very strong cup of tea. Bring in two tea bags from home.
Bring about 100 ml of water to boil in a 150 ml beaker. Add about tip of spatula full of sodium carbonate. Place the tea bags in the boiling water and let them steep for 7 - 10 minutes with a watch glass on the top and the heat on low. Excessive heat can decompose caffeine so do not let the tea dry out.
2. Squeeze the tea bag against the side of the beaker with a stir rod to remove as much of the liquid as possible. Let the solution cool to room temperature.
3. Pour the tea into the separatory funnel. (Make sure that the stopcock is closed). Add about 10 to 20 ml of methylene chloride and shake gently. Vigorous shaking will lead to an
emulsion. …show more content…
Remove the magnesium sulfate by gravity filtration through filter paper.
5. Filter into a pre-weighed 50 ml round bottom flask and remove the solvent through low-pressure evaporation. As the methylene chloride evaporates, the flask will get cold. It may help speed the process to have a large dish or bowl filled with room temperature warm water to keep the flask from getting too cold.
6. Weigh the flask and the product and record the mass and the properties of your crude caffeine.
Data:
Calculation:
Discussion:
My lab was really bad because our round-bottom flask is filled with water and caffeine, which lead higher percent yield.
Error Analysis:
There is one big error in this lab that we may accidentally spilled water into the flask while using low pressure rotary evaporation.
Modification:
We could actually bring it back up into methylene fluoride and may try it again in this experiment.
Conclusion:
We separate the caffeine from teabags that may
Purpose:
The purpose of the lab is to separate caffeine from the teabags by using three techniques, extraction, recrystallization, and melting point determination.
Procedure:
1. In the first step we have to brew a very strong cup of tea. Bring in two tea bags from home.
Bring about 100 ml of water to boil in a 150 ml beaker. Add about tip of spatula full of sodium carbonate. Place the tea bags in the boiling water and let them steep for 7 - 10 minutes with a watch glass on the top and the heat on low. Excessive heat can decompose caffeine so do not let the tea dry out.
2. Squeeze the tea bag against the side of the beaker with a stir rod to remove as much of the liquid as possible. Let the solution cool to room temperature.
3. Pour the tea into the separatory funnel. (Make sure that the stopcock is closed). Add about 10 to 20 ml of methylene chloride and shake gently. Vigorous shaking will lead to an
emulsion. …show more content…
Remove the magnesium sulfate by gravity filtration through filter paper.
5. Filter into a pre-weighed 50 ml round bottom flask and remove the solvent through low-pressure evaporation. As the methylene chloride evaporates, the flask will get cold. It may help speed the process to have a large dish or bowl filled with room temperature warm water to keep the flask from getting too cold.
6. Weigh the flask and the product and record the mass and the properties of your crude caffeine.
Data:
Calculation:
Discussion:
My lab was really bad because our round-bottom flask is filled with water and caffeine, which lead higher percent yield.
Error Analysis:
There is one big error in this lab that we may accidentally spilled water into the flask while using low pressure rotary evaporation.
Modification:
We could actually bring it back up into methylene fluoride and may try it again in this experiment.
Conclusion:
We separate the caffeine from teabags that may