Working with glass test tubes
The glass test tubes that we will be using are very thin glass. To be safe, we should keep them in the test tube stand when they aren’t being observed. If you are inserting the thermometer into the test tube, make sure not to let it touch the bottom of the test tube. Measure the temperature of the liquid above the bottom.
Working with liquid
Some of the working stations have provided safety glasses. Because of Coronavirus, glasses cannot be lent out to students. However, if you happen to own a pair of glasses, please bring them in for extra safety. When you have finished using the test tubes, make sure to discard them in the wash tub provided.
Working with dry ice
When working with dry ice, NEVER handle the pellets with your hands. At -78°C, they can cause burning and frostbite, and will hurt lots!
CORRECT MIXING AND READING TECHNIQUES
For the flick mix technique, use your fingernail to tap against the tube. Make sure to always have the mouth of the tube pointing away from yours and anyone elses face.
Reading a meniscus correctly
A meniscus is the curve in the upper surface of a liquid caused by surface tension. Here are some diagrams to show how to read one correctly.