Flashcards
Heating under Reflux
Flashcards do conjunto (15)
- 1When is refluxed used?To prepare an organic liquid without boiling off the solvent, reactants or products.
- 2What temperature does refluxing boil solutions at?A fixed temperature
- 3Draw a diagram of the apparatus usedstand and clamp
pear-shaped flask
condensor
rubber tubing
heat source - 4Step 1.Assemble apparatus
- 5Step 2Add anti-bumping granules to liquid ensure smooth boiling
- 6When are anti-bumping granules added?Before condensor is fitted and before liqiud is boiled
- 7Why?Enables a liquid to be continually boiled whilst a reaction is taking place
Prevents glassware vibrating - 8Step 3.Apply thin layer grease to ground-glass joint of condenser
- 9Step 4.Place condenser carefully into flask and gently rotate condenser back and forth to provide a good seal
- 10Step 5.Condenser is kept in upright position and clamped loosely as the glass outer jacket is fragile
- 11Why should you never put a stopper in the condenser?As you would have a closed system and pressure would build up inside as heated air is expanded.
- 12Purpose of rubber tubingConnect inlet of condensor to tap and outlet to sink.
- 13Where does water always enter the condenser?At the bottom and leaves at the top
- 14What is the role of the condenser in the reflux reactionEnsures any vapour produced from reaction condenses and drips back into the flask.
- 15What heat source may be used if the reaction is carried out under 100'c?Water bath.
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- O usuário eliminou as informações de disciplina FlashCards sobre Heating under Reflux, criado por Usuário eliminado em 09-06-2018.
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- Criado por josephw weetch · 5 jun 2018
- Copiado por josephw weetch · 9 jun 2018
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