Heat It Safely
Set up lab glassware the right way to heat a liquid.
What this lesson covers
Why it matters
Heat a beaker the wrong way and the glass can crack, or the hot liquid spits out. A few simple steps keep the glass — and you — safe.
Predict first
Before heating a liquid in a beaker over a flame, what should you put between the beaker and the flame?
Heat glassware gently and evenly. A wire gauze on a tripod spreads the flame's heat so the glass doesn't crack from a hot spot, and you never heat a sealed container.
- A wire gauze resting on a tripod — correct
- Nothing — put the beaker straight into the flame
- A sheet of paper
What you do
Put the steps in the right order to heat water in a beaker safely.
Check yourself
Why rest the beaker on a wire gauze?
The gauze spreads the flame's heat evenly so the glass doesn't crack from one hot spot.
Which is safe to heat over a flame?
Never heat a sealed container — trapped gas can burst it. Heat a test tube gently with its mouth pointed safely away.
- It spreads the heat so the glass won't crack — correct
- It makes the water boil faster
- It stops the beaker rolling away
- A little liquid in a test tube, mouth pointed away from people — correct
- A tightly sealed bottle
- A corked, full flask