Purifying Organic Products Flashcards
What can be observed in the collection flask when preparing samples of organic liquids?
Two liquid layers: organic layer and aqueous layer
The organic layer contains the product, while the aqueous layer contains water.
How can you identify the organic layer in a mixture?
Add some water; the layer that increases in volume is the aqueous layer
The organic layer will not increase in volume when water is added.
What is the first step to separate the two layers using a separating funnel?
Ensure that the tap of the separating funnel is closed
This prevents any liquid from escaping during the initial mixing process.
What should be done after pouring the mixture into the separating funnel?
Place a stopper in the top of the funnel and invert to mix the contents
This ensures thorough mixing of the two liquid layers.
What is the purpose of allowing the layers to settle in the separating funnel?
To allow the two layers to separate based on density
The organic layer and aqueous layer will form distinct layers due to different densities.
What should be done after identifying the aqueous layer?
Place a conical flask under the separating funnel, remove the stopper, and open the tap to let the lower layer out
The lower layer is typically the denser aqueous layer.
What is the next step after draining the lower layer into a conical flask?
Place a second conical flask under the separating funnel to collect the organic layer
This ensures that both layers are collected separately.
What should be done to avoid confusion between the two collected layers?
Label the flasks accordingly
This prevents accidental mixing or discarding of the product.
What method can be used to remove acid impurities from an impure product?
Add aqueous sodium carbonate and shake the mixture in the separating funnel
This reaction helps to neutralize the acid impurities.
What gas is released when acid reacts with sodium carbonate?
Carbon dioxide gas
This gas can build up pressure, requiring careful handling.
How should the tap of the separating funnel be handled when releasing gas pressure?
Slowly open the tap while holding the stoppered funnel upside down
This safely releases built-up gas pressure.
What is the final step after removing the aqueous sodium carbonate layer?
Wash the organic layer with water before running both layers into separate flasks
This ensures the organic layer is purified before collection.
