Why do we have them? When we measure things, we want to measure to the place we are sure of and guess one more space.

So, they show the uncertainty in our measurements

Since the marks on this ruler are subdivided as they are, our answer for the length of this nail has 3 significant figures.

However, we only have significant figures when we are measuring something. Counting will give you an exact number.

Lab Equipment

Beaker Holds chemicals during mixing, heating, and storage Acts like a bowl Inaccurate measuring device

Erlenmeyer Flask Holds chemicals during mixing, heating, and storage Acts like a bowl Inaccurate measuring device

Volumetric Flask Holds chemicals during mixing and storage Accurate measurement of a specific volume

Funnel Aids in pouring and filtering process

Watch Glass Acts as a cover during heating and storage Looks like a giant contact lense

Evaporating Dish Container used to allow materials to evaporate

Crucible and Cover Used to hold materials that need to be heated to higher temperatures

Crucible Tongs Used to hold heated crucibles

Bunsen Burner Used to heat materials

Striker Used to light burners

Balance Used to determine the mass of materials

Graduated Cylinder Used to measure liquids accurately Must look at meniscus of the liquid when taking readings

Iron Ring Attaches to ring stand Holds various equipment while they are heated

Buret Clamp Attaches to ring stand Holds burets during titrations

Utility Clamp Attaches to ring stand Holds various thin equipment while they are heated

Goggles Protect eyes during experiments

Ring Stand Used to support devices during laboratory procedures

Buret Used to accurately and slowly add liquids Used most often in titration experiments

Thermometer Used to measure the temperature of various materials

Gas-collecting tube Tube used to collect gases. Usually used in the inverted position

Test Tube Used to hold small samples during heating and storage

Test Tube Rack Used to hold multiple test tubes

Test Tube Holder Used to hold one test tube, usually during heating or transporting test tube

Forceps Used to pick up and separate small solids

Spatula Used to scoop small quantities of solids Can be used to scrape the inside of various equipment

Mortar and Pestle Used to crush and grind materials

Pipet Used to dispense small quantities of liquids

Stoppers Come in various sizes Used to block openings of various equipment