Name:
Period:
Technique (Bunsen Burner) Lab – Bubble Wands
Introduction: A number of important procedures need to be mastered in order for you to perform the
laboratory investigations in this course. You will need to know how to use lab equipment properly, use
a Bunsen burner, make accurate measurements, handle solid and chemical solutions, heat materials
safely, transfer liquids properly, filter a solution, perform a titration, and many more. All of these are
called lab techniques – in this lab you will master the technique of lighting, adjusting, and properly
using a Bunsen burner! Make sure you are able to do this, because after this lab you will be expected to
know how to light and use a Bunsen burner properly. Prior to every lab Mrs. Gonzalez will show you
any new lab technique you are responsible for mastering during that lab! Questions about lab techniques
will be on all of your exams!
Purpose: Students will: 1) learn and demonstrate the proper lighting, adjusting, and use of a Bunsen
burner; 2) read and follow directions; 3) learn how to properly cut glass tubing; 4) learn how to fire
polish.
Safety:
Wear goggles and apron.
Confine long hair and loose clothing.
Hot glass looks like cool glass. Be careful with the cut ends of glass tubing.
Materials:
glass tubing
wash bottle
Silicone
tubing
glitter
striker
ring stand
glass cutter
Baby oil
Prelab Questions:
1. Name four lab techniques you will learn throughout this year:
2. How are the Bunsen burners shown in Procedure 1 alike and how are they different?
Procedures:
1. Put on your safety goggles and lab aprons. Before you begin to work with your Bunsen burner,
compare it to the pictures of the two common lab burners below:
Burner A
Burner B
Gas
Inlet
(main
gas
valve
should
be
fully
open)
Burner Tube
Air Vent
Gas Inlet
(regulates gas
flow with the
main gas valve)
Gas Control Valve
(regulate gas flow with this
valve)
2. Most Bunsen burners are constructed in a similar fashion. There is an inlet for the gas, an
adjustment for the flow of gas, and an adjustment for the flow of air. A proper mix of air and gas
will yield a faint blue flame for maximum heat and minimum soot. Identify the gas adjustment and
the air adjustment on your burner. Before you light the burner, turn the air adjustment to allow as
little air as possible.
J Hodgson; Georgetown High School
3. Before you light the burner, check to make sure all students nearby are wearing their safety goggles.
Lighting the burner is a one-person job. Have a striker ready before you turn on the gas. Light the
burner by turning on the gas and holding the match or striker above the barrel of the burner.
4. Adjust the flame to a blue color by changing the flow of air and the flow of gas. Look at the figure
below to help identify the hottest part of the flame.
5. You adjust the height of the flame by adjusting the amount of gas that is flowing into the burner.
You adjust the color of the flame by changing the amount of airflow to the flame. If there is not
enough air the flame will be yellow or orange – this is called an inefficient flame and should
NEVER be used during a lab. It will cause your glassware to become black with soot. It is also
called a cool flame, which means it will take a longer period of time for you to heat a substance.
The ideal flame is about 8 cm in height, blue in color, and has a double cone. The hottest part of this
flame is at the top of the inner blue cone – anytime you heat something your item should be placed at
the top of that inner cone. Draw a dog (stick figure dogs are fine) by your name on your prelab.
6. Have Mrs. Gonzalez check your flame and then turn it off and go on to the next part of the lab.
7. Obtain a piece of glass tubing from the front table. Cut a piece of glass tubing using the glass cutter
and a ruler. (The glass tubing has already been measured and marked). To use the glass cutter,
place the glass tubing into the mouth of the glass cutter. Hold the glass tightly with one hand and
rotate the glass cutter. This scores the glass. DO NOT USE A SAWING MOTION OR
REPEATED SCRATHING! Grasp the glass in both hands with the scratch facing away from you
and both thumbs directly behind the scratch. Push firmly with the thumbs and pull with your
fingers. The glass should snap with a clean break.
8. Light and properly adjust your Bunsen burner. Fire polish both ends of the glass tubing. To fire
polish rotate one end of the glass tube in the hottest (top of inner cone) part of the flame until the
sharp edges have softened and become rounded. DO NOT HOLD THE TUBING IN THE FLAME
TOO LONG. THE HOLE IN THE TUBE WILL CLOSE. Place the hot glass on wire gauze to cool.
Make sure one end of the tube is cooled before fire polishing the other end. Once both ends have
been fire polished allow your glass to cool.
9. Once cool obtain a piece of masking tape and write your name and period and tape it to your glass
tubing.
10. Place a plug of Silicone (found at the front table) at one end of the tubing. Place glass tubing –
SILICONED END UP – in the cup on the front table. It needs to dry until the next class period.
11. Once dry, obtain your glass tubing. Using a small piece of paper fold to make a funnel to be used to
place glitter into glass tubing. Place glitter into glass tubing using paper as a funnel. Fill until glitter
takes up approximately 1/4 the length of the tube.
12. Fill the remainder of the tube with baby oil. Leave about 1cm-2cm of space at the top of the tube in
order to plug the other end. Plug end with Silicone. Silicone should NOT be touching any of the
baby oil in your bubble wand.
13. Place bubble wand – WET SILICONE END UP – in the cup on the front table. You may pick it up
next class period.
Data & Calculations: None
Conclusion Questions:
J Hodgson; Georgetown High School
1.
2.
3.
4.
5.
6.
Draw the setup of a Bunsen burner with a properly adjusted flame – label all parts.
Where is the hottest part of a flame?
What is the purpose of mixing air with the gas when using a Bunsen burner?
What is fire polishing?
What is an efficiently burning Bunsen burner?
What is an inefficiently burning Bunsen burner?
J Hodgson; Georgetown High School