reflux Flashcards
What is the advantage of heating under reflux?
Enables liquid to be continuously heated, prevents volatile components evaporating and the flask boiling dry.
Why might you use a heating mantle rather than a naked flame?
Safer if using flammable liquids or if there is a crack/leak in the glassware.
What is the purpose of anti-bumping granules in a boiling mixture?
prevent large bubbles from forming and ensure the liquid boils smoothly
preventing it from boiling over into the condenser and contaminating products with impurities
How should a condenser be positioned to allow proper operation?
should be tilted down slightly to allow any liquid to run into the collection flask.
Where should the bulb of the thermometer be placed when measuring the boiling point in a distillation setup?
bulb should be at the T junction connecting to the condenser to correctly measure the boiling point.
How should water be directed through the condenser for maximum cooling efficiency
Water must enter at the lowest point and leave at the highest point of the condenser to ensure it is filled with water and maximize heat transfer for condensation.
Why must the collection flask not be sealed to the condenser in a distillation setup?
To avoid creating an airtight system, which would prevent air from escaping as it expands when heated, potentially causing the apparatus to crack.
colour change
orange to green
Cr207 2- to Cr3+
