In the first experiment (from page 33 in Catalyst) you will learn how to use the analytical balances in Room 6036. You will be given an unknown metal or glass sample in a glass vial that is to be weighed as carefully as possible. The second exercise involves weighing a known volume of a liquid in order to calculate its density. Part 3 of this lab requires you to find the density of an unknown solid by displacement of water in a measuring cylinder.
The Analytical Balance
After you press the ON button you will see the readout to 3 decimal places or 0.001 g as is required for the first exercise.
To zero the balance you press the TARE button as shown here. These balances are very expensive and should be cleaned if you spill anything inside them.
You will measure a volume of an unknown liquid using the graduated cylinder. Place a piece of white paper behind the cylinder to help you see the markings more easily.
For Parts 2 and 3 of this exercise you will use the analytical balance to find the weight of a known volume of liquid. Using D=M/V you are then able to find the density of the unknown liquid. For the unknown solid you will weigh the sample and then record how much water is displaced by the solid after you put it in the measuring cylinder.