1. Laboratory Equipment
An Introduction

2. What is your glassware?
Each table has a piece of laboratory equipment on it.
As a group, answer the following questions?
What is it?
What do you use it for?
Why would you choose it over another?
How would you use it?
When would you use it?

3. Glassware Beaker Erlenmeyer Flask Graduated Cylinder Volumetric Flask
Buret
Pipette

4. Glassware
Only use glassware that had been thoroughly and properly cleaned and dried
Glassware that has been cracked or etched should be discarded - glassware abnormalities can lead to inaccurate measurements
Use the appropriate size of glassware to ensure accuracy

5. Beakers
Beakers are used to collect a sample, to mix chemicals and to hold chemicals
A beaker has measurements, but is not used to measure exact amounts of a chemical
Beakers come in various sizes

6. Erlenmeyer Flask
Erlenmeyer Flasks are used to collect the titrant during titrations
The narrow neck prevents excess splashing
Cannot be used to measure exact amounts of a chemical

7. Graduated Cylinder
Graduated cylinders are used to measure sample, standard, reagents, etc.
Measurements are only as accurate as the cylinder is marked

8. Reading a Volume
Always read the volume of a liquid at the bottom of the meniscus 50 40 30 20 10

9. Volumetric Flask
Volumetric Flasks are used to measure a specific volume of sample or to prepare solutions; it is a more accurate method than either pipetting or using a graduated cylinder for large volumes

10. Burets
Burets are used to deliver larger volumes of reagent in smaller quantities.
Do not use a stopcock that leaks or is damaged in any way
Make sure that the seal on the stopcock is tight

11. Pipettes
Etched rings on pipettes are “blowout”; if the measurement ring is not etched into the glass, then it is “to deliver”
If a reagent or solvent is accidentally sucked into the bulb or pipette pump, thoroughly clean the apparatus and re-measure the reagent or solvent

12. Pipette Bulbs and Pumps
Bulbs and pumps are used to draw up the liquid and then to deliver the liquid

13. Using Pipettes and Burets
Choose the appropriate piece and size of equipment
When measuring volume, always read the measurement at the bottom of the meniscus
Hold the pipette or buret straight vertically and read the volume at eye level
Always use clean pipettes and/or burets

14. NEVER MOUTH PIPET!

15. Accessories Crucible and Evaporating Dish Tongs Crucible Tongs
Beaker Tongs
Test Tube Tongs
Clay Triangle
Wire Gauze
Watch Glass
Ring Stand

16. Crucible and Evaporating Dish
Porcelain cups that can withstand high heat
Used with a bunsen burner to heat sample

17. Tongs
Tongs are used to handle specific equipment that is hot, going to get hot or has the potential to splash
Crucible Tongs
Beaker Tongs
Test Tube Tongs

18. Clay Triangle and Wire Gauze
Used when heating equipment with a bunsen burner or cooling hot glassware

19. Watch Glass
Allows you to observe a chemical reaction in a beaker or flask without the hazard of splashing or sputtering

20. Ring Stand
Used to clamp a buret, test tube or other glassware

21. Equipment pH Meters and probes Stir Bars/Stir Plates Hot Plate
Bunsen Burner

22. pH Meter pH probes are very sensitive to change
Always keep the probe in a solution when not in use
Calibrate the meter according to the manufacturers recommendations
Allow the meter to stabilize before taking a measurement

23. Stir Plate
Stir plates are used to mechanically agitate the sample to assure a homogenous mixture
Stir plates must be used during a titration to assure the proper chemical reaction with the entire solute
Do not reuse a stir bar until it has been cleaned

24. Hot Plate
Hot plates are used to heat chemicals instead of a bunsen burner
Remember that a hot plate is a source of ignition; therefore, do not use any flammable materials around the hot plate
Samples may contain contaminants that cause popping or splattering of the sample; to avoid this, use a boiling stone or an appropriately sized beaker

25. Stir/Hot Plate
Stir Plates and Hot Plates are often combined into one apparatus

26. Bunsen Burner A bunsen burner is used for heating samples.
The fuel is natural gas.

27. Parts of a Bunsen Burner
The parts of the burner include:
gas inlet
burner tube (adjustable)
air control vent
gas control valve

28. Lighting a Bunsen Burner
To light the burner,
step 1: turn on the gas
step 2: open the gas control valve 1/4 to 1/2 turn
step 3: hold the striker at a 45o angle and ignite the flame

29. Parts of the Flame

30. Adjusting the Flame Air adds Oxygen which is necessary for combustion
To make the flame burn hotter and larger, open the air mixture valve accordingly
To make the flame burn cooler and smaller, close the air mixture valve accordingly
Opening the gas valve will add more fuel to the mixture but not more Oxygen, and cause incomplete combustion

31. Color Indicators
Different flame types of a Bunsen burner depend on oxygen supply.
What does the flame on the left tell you?
A rich fuel mixture with no premixed oxygen, incomplete combustion produces a yellow sooty flame.
What does the flame on the right tell you?
A fuel and oxygen mixture allows for complete combustion and a hot, blue flame.

32. Color Indicates Temperature
Yellow flame (also called a safety flame) at around 1,000°C.
Increasing oxygen supply creates a blue appearance
The coolest part of a flame will be red, then progress to orange, yellow, and white as the temperature increases