This document provides instructions for a chemistry lab on the use of Bunsen burners and observing candle flames. Students will identify the parts of the Bunsen burner and different flame types. They will then observe a burning candle before, during, and after combustion, recording physical properties. Students are asked to analyze the differences between qualitative and quantitative observations, physical and chemical properties, and observations and inferences. They will also explain what really burns in a candle and define chemistry as it relates to this lab. The goal is for students to gain understanding of Bunsen burners, candle flames, and the scientific process through hands-on experimentation and analysis.
Understanding Partial Differential Equations: Types and Solution Methods
# 1 Bunsen bunner and flame zones.docx
1. PREAICE /AICE Chemistrylabs-
KGCHS
Practice 1 Teacher: - Ingrid Echeverria
9-11
PRACTICE LAB N° 1
1. Title: USE OF THE BUNSEN BURNER - STUDY OF THE FLAME
2. Objective:
▪ - To recognize and identify the Bunsen burner uses and parts.
▪ - To recognize and analyze parts of flame.
▪
3. Problem questions.
Does the color of a candle affect its burn rate?
Does wick size affect the burn rate of a candle?
Does wick size affect flame height?
Does wax type affect a candle’s burn rate?
Does wax type affect flame height?
Does wax type affect the brightness of the flame?
What is the temperature of a candle flame?
Is the temperature of a flame uniform?
¿Do wax pool and flame temperature correlate?
Does fragrance affect a candle’s burn rate?
Does fragrance impact flame height?
4. Grouping and Material
Grouping: Students will be grouping in WORKSTATIONS.
Individual Material
�
- 1 candle.
�
- 1 lighter.
� 1 dish
Material per Team
�- Pre-laboratory flow chart (FLUX DIAGRAM)
A sample preparation
�- Prepare a safe table, close to the sink is preferable.
2. Laboratorio1 Teacher: - IngridEcheverria
9-11
5. Background Information.
The Bunsen burner is a type of lighter used in scientific laboratories to heat, melt, sterilize
and / or evaporate substances. This appliance causes flames through the combustion of air and gas,
and, as a heat source, it provides not too high temperatures.
The Bunsen burner is composed of a flat and heavy base through which the gas is
introduced. The latter flows in an upward direction through a vertical tube with some perforations
to let the air penetrate. Thanks to the so-called “Venturi Effect”, the above mixture becomes
flammable and
comes out as a flame from the top of the tube.
When using a Bunsen burner, you must take into account the following recommendations. To
avoid accidents, a single person must handle it. Before connecting the hose to the gas supply, its
condition will need to be checked. Then, you must make sure that there’s no presence of leaks. Do
not wrap the hose around any appliance, and do not open the gas valve prematurely.
A Bunsen burner is an instrument in scientific laboratories whenever a source of heat is
required, whether it is to produce heat, accelerate a chemical reaction, effect a physical change,
and to sterilize samples or chemical reagents. It is widely used in laboratories because it provides a
constant, hot, smokeless flame that does not produce soot deposits when heating objects.
Its name has derived from the German chemist Robert Wilhelm Bunsen (1811-1899), who
adapted William Faraday's concept of the gas burner in 1855 and popularized its use. The burner
has a heavy base into which the gas supply is inserted.
The lower part of the vertical tube has a hole that permits gas into the burner tube. Is
also, the collar that has holes allowing, by adjusting the position of these holes, (figure1), the
regulation of oxygen airflow to mix with the gas. The result is a flammable mixture at the outlet of
the burner tube where combustion occurs resulting in a flame.
The amount of gas and heat from the flame can be controlled by adjusting the size of the
holes in the collar. If more air has been allowed to pass and mix with the gas, the flame burns at a
higher temperature (appearing with a blue flame color).
If the collar holes are closed, the gas only mixes with atmospheric oxygen at the top of the
burner producing a flame of cooler temperature with reddish or yellowish color.
The heat is caused by the combustion of gas, which could be coal, acetylene, propane,
butane or natural gases, according to the design of the lighter and your specific needs.
3. Laboratorio1 Teacher: - IngridEcheverria
9-11
The Bunsen burner has the following parts:
Figure 1. Parts of a Bunsen burner.
Flames of a Bunsen burner
a. Safety Yellow Flame (luminous flame)
“Coolest" flame is a yellow / orange color.
Approximately 300°C to 900°C
It is never used to heat anything,
only to show that the Bunsen burner is on.
Figure 2: Yellow and safety flame
Lighting Bunsen burner
Connect tube from Bunsen burner to desk
outlet valve.
Close needle valve or stopcock and collar.
Open desk outlet valve fully.
Open needle valve or stopcock 1/2 turn.
Use the spark lighter to light the flame.
Adjust collar and needle valve until you see a
blue flame.
Check that the holes are closed.
The holes can be adjusted to let in more or
less air by turning the collar.
Adjusting the flame
Close the Barrel → less oxygen → weaker,
yellow flame.
Open the barrel → more oxygenated →blue
flame –
Blue flame is desired: hotter and more
controlled.
4. Laboratorio1 Teacher: - IngridEcheverria
9-11
b. Normal Blue Flame (Non Luminous flame)
Medium flame, or blue flame or the invisible flame.
Difficult to see in a well-lit room.
Most commonly used flame.
Approximately 500°C to 1000°C
Figure 3: Normal Blue flame.
c. Roaring flame (Half Luminous flame).
Characterized by a light blue triangle in the middle
and produces a noise. It is the hottest flame,
approximately 900°C to 1500°C
Figure 4: Roaring blue flame
Table 1. Types of flame
Air Hole Type of flame When do we use this
type of flame?
Air hole open Roaring flame To heat things up fast
Air hole half open Blue flame To gently heat things up
Air hole closed Yellow safety flame When we are not using it
Bunsen burner safety
1. Always open the workstation outlet valve fully. Regulate the gas supply to the burner by
the needle valve or stopcock.
2. Always extinguish your burner by turning off the workstation outlet valve and then
closing the needle valve and collar.
3. If there is an accident, always shut off the workstation outlet valve immediately.
4. Designate one person in the group who will be responsible to maintain the burner and
flame.
Figure 5. Types of flames.
5. Laboratorio1 Teacher: - IngridEcheverria
9-11
Structure and parts of a candle flame
A flame is a space/zone of burning gas or vapor fuel to cover a region with a constant shape
as maintained by the supply of fuel. The fuel can be solid, liquid, or gas but will always burn as a
gas.
Figure 7. Structure of a flame
6. Laboratorio1 Teacher: - IngridEcheverria
9-11
Figure 6. Parts of a flame.
How candles burn?
All waxes are essentially hydrocarbons, which means
they are largely composed of hydrogen (H) and carbon (C)
atoms.
When you light a candle, the heat of the flame melts
the wax near the wick. This liquid wax is then drawn up the
wick by capillary action.
The heat of the flame vaporizes the liquid wax (turns
it into a hot gas) and starts to break down the hydrocarbons
into molecules of hydrogen and carbon. These vaporized
molecules are drawn upwards into the flame where they react
with oxygen from the air to create heat, light, water vapor
(H2O) and carbon dioxide (CO2).
Approximately one-fourth of the energy created by a
candle’s combustion is given off as heat radiates from the
flame in all directions. Enough heat is created to radiate back
and melt more wax to keep the combustion process going until
all fuel is spent.
Figure 8. How a candle
burns.
7. Laboratorio1 Teacher: - IngridEcheverria
9-11
It takes a few minutes when you first light a candle for this combustion process to stabilize. The
flame may flicker or smoke a bit at first, but once the process has stabilized, the flame will burn
cleanly and steadily in a quiet teardrop shape releasing carbon dioxide and water vapor.
A quietly burning candle flame is a very efficient combustion machine, but if the flame gets
too little or too much air or fuel, it can flicker or flare. As a result, unburned carbon particles
(soot) will escape from the flame before they can fully combust. The wisp of smoke you sometimes
see when candle flickers is caused by unburned soot particles that have escaped from the flame due
to incomplete combustion.
6. Procedure
A- PROBLEM QUESTION
1.) PICK ONE of the problem questions you will find in numeral 3, and work in this one you and
your team to write the hypothesis.
2.) You and your team must do the necessary procedures, experimentations and observations to
answer your problem question and test your hypothesis.
PARTS OF A BUNSEN BURNER.
3.) Carefully observe a Burner Bunsen, identify each one of its parts. Sketch a picture of it,
label every part.
4.) Watch each one of the flame’s types and draw them in your report. (You can take pictures
too, but you must print them and paste them in your lab report).
B- ZONES OF THE FLAME.
5.) Place a candle on a plate. (You may want to gently heat the bottom of the candle with a flame
so that melted wax will adhere it to the dish.) Sketch a picture of your candle and label it.
8. Laboratorio1 Teacher: - IngridEcheverria
9-11
6.) Record at least 6 observations of the candle before burning. Feel free to use measurement
tools of your choice. You may have available (ruler, food scale, lab scale, etc.) Label these
observations as “Before Burn” In a Data Table # 1
Table #1 Before Burn
7.) Make sure the candle is in a place where it is safe to let it burn for 5 minutes.
8.) On your paper, record at least 6 observations of the candle and its support. Label these
observations "During Hot" in Data Table # 2.
Table # 2 During hot
9.) Extinguish the candle flame.
10.) On your paper, record at least 6 observations of the candle and its support. Label these
observations "After Burning" in your Data Table # 3. (Make your comparisons and análisis.
9. Laboratorio1 Teacher: - IngridEcheverria
9-11
Table # 3 After burning
7. Analysis.
1.) Describe the difference between qualitative and quantitative observations. (You may have to
access to internet for this).
2.) A.) Describe the difference between physical and chemical properties. (You may have to
access internet for this).
B). In your tables, using color highlighters, indicate which of your observations deal with
physical properties and which are chemical properties. (Be sure to include a key).
3.) A.) Describe the difference between “intensive” and “extensive” properties. (You may have to
access the internet)
B) In your tables, using color highlighters, indicate your observations with reference to
intensive properties and extensive properties. (Be sure to include a key).
4.) A.) Describe the difference between observations and inferences.
B.) Circle the inferences you made in your observations.
5.) Explain what in a candle that really "burns"? Write a short statement or draw a labeled
diagram that addresses this question?
6. Make a drawing of your candle labeling its parts. This must be in your observations.
7.) What is chemistry? Write a definition of the term and describe how the definition relates to
this laboratory.
10. Laboratorio1 Teacher: - IngridEcheverria
9-11
8. References.
▪ Observations of a Burning Candle * Make *up Assignment. 2 Feb.2015:
https://studylib.net/doc/6630600/observations-of-a-burning-candle---make--up-
assignment
▪ Anthony P. Hamins, Matthew F. Bundy , Scott E. Dillon. (2005, November 01).
Characterization of Candle Flames.
https://www.nist.gov/publications/characterization -candle-flames
▪ Gelves Cardenas, Andrea. 2017. Mechero Bunsen y studio de la llama.
https://www.academia.edu/37471989/EL_MECHERO_DE_BUNSEN_Y_ESTUDIO_DE
_LA_LLAMA_PRACTICA_2_INFORME
▪ Millner, Deborah. 27 October. 2015. Experimental Procedure Lab 402, 406, 704. Clay
triangle Bunsen burner A. Sample Preparation 1. Prepare a clean crucible Support the
crucible and lid on. https://slideplayer.com/slide/3920398/
11. Laboratorio1 Teacher: - IngridEcheverria
9-11
HOW YOU MUST DO YOUR LAB REPORT.
Your Lab Report must have all the parts listed below, and it must be handwritten.
1. Title: It is always given in your guide.
2. Objectives: Your teacher must give you some, you can find others according to your problem
questions and hypothesis.
3. Materials List: Make a list of the material you used and write the characteristics of each.
4. Background Information: First, research your lab experiment. Then, write at least one page
with relevant information from your research of the topic.
5. Problem Statement: Having read the background information given to you, you and your group
must find a problem statement for your own lab report.
6. Hypothesis: Write your “educated guess”.
7. Observations: Using tables, graphics, diagrams, drawings and pictures, you must write your
observations in your lab report. In this case you must do.
8. Analysis and questions: You must follow the steps provided and answer the questions or
analysis that this practice has asked you.
9. Conclusions: Reread the Objectives, Problem Statement, and Hypothesis in mind; write a short
paragraph that highlights two or three things you learned in this lab. These should be things
you didn't know before starting this lab.
12. Laboratorio1 Teacher: - IngridEcheverria
9-11
10. References: All your information sources must be written here. All the references that you
used to document your lab report. See references above.