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What is the purpose of refluxing?
The main purpose of refluxing a solution is to heat a solution in a controlled manner at a constant temperature. For example, imagine that you want to heat a solution to 60oC for one hour in order to conduct a chemical reaction.
Why is reflux used in distillation?
The purpose of reflux is to provide down-flowing liquid throughout the rectification section to contact with the up-flowing vapor in order to achieve stage-by-stage equilibrium heat and mass transfer and, hence, purification of the top product.
What happens during reflux?
Reflux involves heating the chemical reaction for a specific amount of time, while continually cooling the vapour produced back into liquid form, using a condenser. The vapours produced above the reaction continually undergo condensation, returning to the flask as a condensate.
Why is reflux used in hydrolysis?
The reaction with pure water is so slow that it is never used. The reaction is catalysed by dilute acid, and so the ester is heated under reflux with a dilute acid like dilute hydrochloric acid or dilute sulphuric acid. To make the hydrolysis as complete as possible, you would have to use an excess of water.
What is internal and external reflux?
The liquid that is re-introduced into the tower is called external reflux. As the external reflux cools the top of the tower, vapors made of heavier fraction condense and liquid made of heavier faction flows down the tower and it’s referred to as internal reflux.
What is reflux in organic chemistry used for?
Reflux involves heating the chemical reaction for a specific amount of time, while continually cooling the vapour produced back into liquid form, using a condenser. The vapours produced above the reaction continually undergo condensation, returning to the flask as a condensate. In this regard, what is reflux in organic chemistry used for?
How to set up reflux in a chemistry lab?
1 How to set up a reflux apparatus. 2 Reflux is a chemistry lab technique that heats a solution, produces vapor, and. 3 then condenses and returns the outgoing vapor into its original mixtures. 4 Reflux is widely used in undergraduate organic chemistry labs. 5 Before doing this activity, students should have experience using boiling chips,
Do you know the true meaning of reflux?
We always see this reaction condition called “ Reflux ” when we study Organic Chemistry and their reactions. I realised alot of students do not understand the true meaning of a reflux. This includes some of my JC2 and IB students who recently join our A-Level H2 Chemistry Tuition Classes. So what really is Reflux?
What happens to the reaction mixture under reflux?
As such, most organic chemicals are quite volatile, and if heated they will evaporate and be lost. The solution to this problem is to heat the reaction mixture under reflux. Diagram below shows the basic set-up of Refluxing: