Laboratory techniques
Laboratory techniques are the techniques of handling the various pieces of apparatus.
Basic techniques
[change | change source]Handling of chemicals
[change | change source]Ways to dissolve a solid in a liquid or to mix two liquids in a test tube:
- Shake the test tube gently
- Stir with a glass rod
- Tap the bottom of the test tube with your finger
- Pour the contents to and fro between two test tubes
- Stopper the test tube and shake
Heating techniques
[change | change source]- Hold the material over a naked flame
- Put the material in a water bath
- Use a type of hairdryer called a "heat gun" to blow hot air at the material.
Collecting gases
[change | change source]- Upward and downward delivery
- Over water
- Gas syringe
Drying substances
[change | change source]- Leave the mixture at room temperature to evaporate on its own.
- Put the substance in an "oven" which heats it gently and removes water vapour.
Smelling gases
[change | change source]- Never smell a gas directly.
- Waft a gas towards yourself if it is reasonably safe to smell it.
- Never smell a gas that is toxic or otherwise dangerous.