How to Make a Reflux Condenser

A test tube can make an effective reflux condenser.

There are a variety of reasons when it may be necessary to boil a small amount of liquid continuously, from creating chemical reactions to making a humidifier. Boiled liquids evaporate, which means the liquid needs to be constantly replaced. This is where a reflux condenser is helpful. This equipment catches the evaporated gases and cools them, causing them to return to liquid state and boil again. Reflux condensers are relatively easy to make.

Things You'll Need

• Glass test tube
• Test tube stopper with 1 inch diameter hole
• Rubber tubing with 1 inch diameter
• Test tube holder or vase

Instructions

1. Ensure the stopper perfectly fits in the top of the test tube.

2. Slot the rubber tubing through the hole in the stopper, until the rubber tubing will reach halfway down the test tube.

3. Place the test tube into a test tube holder, ensuring it is securely held in place.

4. Pour boiled water into the test tube until it is just over halfway full.

5. Place the test tube stopper into the test tube.

6. Point the rubber tubing into the desired direction if using it as a humidifier, or tie it to prevent gases from escaping.

Tips & Warnings

• Always wear gloves when holding the test tube, as the glass may heat up after boiling water has been added.

References

• OCR A2 "Chemistry A Student Book"; Dave Gent and Rob Ritchie; 2008