What is the purpose of a reflux apparatus?
A reflux condenser is an apparatus commonly used in organic chemistry to prevent reactant or solvent loss in a heated chemical reaction. For chemical reactions that need to be carried out at elevated temperatures over long periods of time a reflux system can be used to prevent the loss of solvent through evaporation.
What is Dean Stark apparatus used for?
The Dean–Stark apparatus, Dean–Stark receiver, distilling trap, or Dean–Stark Head is a piece of laboratory glassware used in synthetic chemistry to collect water (or occasionally other liquid) from a reactor.
What is reflux apparatus?
A reflux apparatus allows for facile heating of a solution, but without the loss of solvent that would result from heating in an open vessel. In a reflux setup, solvent vapors are trapped by the condenser, and the concentration of reactants remains constant throughout the process.
What is a reflux drum?
Reflux is that portion of a tower’s condensed overhead liquid product that is cycled back to the top of the tower where it flows downward to provide cooling and condensation of the upflowing vapors. …
What equipment is used for reflux?
Equipment for Distillation and Reflux Heat source – Bunsen burner, water bath, oil bath or electric hot plate. Bottle flask – use a round bottle flask for distillation and a pear-shaped flask for reflux. Thermometer. Condenser.
How does a reflux apparatus work?
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.
What is distillation apparatus?
The distillation apparatus, commonly called a ‘still’, consists of a vessel for plant material and water, a condenser to cool and condense the vapour produced and a method of collection, or ‘receiver’. This is then heated to boiling point and the steam (water vapour) carries out the volatile oils.
Why is toluene used in Dean-Stark apparatus?
This is an advantage when using the Dean-Stark trap to influence equilibria, because it will ensure the continuous removal of water. Upon heating the reaction mixture, the formed toluene/water azeotrope will distill over, condense in the condenser, and flow into the Dean-Stark trap.
What is reflux condenser?
A reflux condenser, also called a vent condenser or knockback condenser, is a vertical tube-side condenser in which the vapor flows upward, as indicated in Figure 11.7. These units are typically used when relatively small amounts of light components are to be separated from a vapor mixture.
How is a reflux apparatus used in a laboratory?
Laboratory reflux apparatus for heating a chemical reaction. A mixture of reactants and solvent is placed in a suitable vessel, such as a round bottom flask. This vessel is connected to a water-cooled Liebig or Vigreux condenser, which is typically open to the atmosphere at the top.
What kind of setup is needed for reflux?
Joints. 9. Recrystallization A simple reflux setup for a recrystallization consists of an Erlenmeyer flask with an watch glass with some ice cubes on the top (see below). The solvent will boil and condense at the cold watch glass and drip back into the Erlenmeyer flask.
How does reflux occur in a laboratory distillation?
Reflux in laboratory distillation. At steady state conditions, the vapor and liquid on each tray is at equilibrium. Only the most volatile of the vapors stays in gaseous form all the way to the top. The vapor at the top of the column then passes into the condenser, where it cools until it condenses into a liquid.
How long does it take to set up reflux apparatus?
Fischer Esterification reaction using reflux technique in organic chemistry lab. Normally, the whole process including the setup and the reaction will take about 2 hours. However, the general principles and the instructions on setting up the reflux apparatus can be applied to any reactions that needed to be heated for a long time.