1. 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.

2. So, they show the uncertainty in our measurements

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

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

5. Lab Equipment

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

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

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

9. Funnel
Aids in pouring and filtering process

10. Watch Glass Acts as a cover during heating and storage
Looks like a giant contact len

11. Evaporating Dish
Container used to allow materials to evaporate

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

13. Crucible Tongs
Used to hold heated crucibles

14. Bunsen Burner
Used to heat materials

15. Striker
Used to light burners

16. Balance
Used to determine the mass of materials

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

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

19. Buret Clamp
Attaches to ring stand
Holds burets during titrations

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

21. Goggles
Protect eyes during experiments

22. Ring Stand
Used to support devices during laboratory procedures

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

24. Thermometer
Used to measure the temperature of various materials

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

26. Test Tube
Used to hold small samples during heating and storage

27. Test Tube Rack
Used to hold multiple test tubes

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

29. Forceps
Used to pick up and separate small solids

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

31. Mortar and Pestle
Used to crush and grind materials

32. Pipet
Used to dispense small quantities of liquids

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

34. So, let us practice with reading different pieces of equipment

35. Answer to Worksheets Scales 622.89 g 153.70 g 200.54 g 128.192 g

36. Answer to Worksheets Thermometers Liquid Volume 68.0  56.0 mL -2.8 
11.0 
-1.1 
28.1 
16.0 
8.0 
-11.5 
98.7 
Liquid Volume
56.0 mL
4.35 mL
23.7 mL
16.8 mL
76.0 mL
5.3 mL
32.0 mL
3.5 mL
47.0 mL

37. Instruments around the room
Beaker
Buret
Volumetric Flask
Graduated cylinder
Scale
Erlenmeyer Flask
Thermometer

38. Homework
Look through your textbook. Find 10 pictures that show a piece of chemical equipment being used. Name the page, the piece of equipment and describe how it is being used.