Bunsen Burn Lab
How do Bunsen Burners Work?
Problems:
How should a Bunsen burner be lit and adjusted to attain a blue flame?
What is the hottest part of a Bunsen burner flame?
Is burning the gas a chemical or physical change? Is it endothermic or exothermic?
Hypothesis:
The Bunsen burner should be lit by striking the match first, turning on the gas, igniting the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame. I predict that the hottest part of the Bunsen burner flame is the tip of the flame. The gas burning is a chemical change. It is exothermic.
Background Information:
Often a chemist needs to heat materials. The Bunsen Burner is one of the most effective ways of doing this. Burners …show more content…
come in a variety of designs but operate on the principle of mixing gas with air to produce a hot flame. Bunsen burner’s have two areas for burning gas/air:: the primary, colored flame, and an outer, almost colorless, flame. A Bunsen burner mixes air with gas to produce a hot flame. A blue flame is the most desirable flame because it is the hottest and has the correct amount of oxygen for complete combustion. A red flame shows incomplete combustion and a lower temperature. Essentially, the the blue flame has the right amount of oxygen and the red flame is burning only the gas.
Materials:
Matches
Water
Pin
Index Card
Equipment
Bunsen Burner
Beaker
Thermometer
Ring Stand/Ring/Wire Sheet
Gas Hose
Parts of a Bunsen Burner:
A: Barrel - Where gas and air are mixed
B: Collar - Adjust the air intake
C: Air intake openings - air centers here
D: Gas intake tube - Gas enters burner from table source.
E: Gas Flow Valve - regulates flow of gas (can be controlled from table gas valve)
F: Base - Supports burner
Safety:
Remember to tie back your hair and make sure your clothes are not baggy. Be sure to keep your area free of loose paper and always have a person monitoring the burner. Remember that hot glass looks the same as cold glass.
Procedure:
Part 1: Lighting the Burner
First, connect the hose to the hose outlet. Clear the area of flammable objects (including clothing and your hair). Next, turn the barrel so that the air intake openings are closed, and open it three full turns. Open the gas flow valve on the table and light the burner. Adjust the barrel so that the flame is pale blue with a dark blue inner cone (Figure 1). What happens to the flame if the barrel is turned counter clockwise? (Place in Qualitative Data section) What happens to the flame if the barrel is turned clockwise fully (Place Qualitative Data section)?
Part 2: Finding the Hottest Part of the Flame
First, set up the support stand, ring, and wire screen as shown in the photos (Figure 2). Then, position the ring clamp so that the beaker is at the base of the flame. Put 100 mL of water into the beaker and record the starting temperature of the water on your data sheet. After that, heat the water for two minutes (Figure 3). Make sure to record the temperature of the water every 15 seconds. Finally, repeat this procedure for positions A, B, C, and D using fresh water each time (Figure 2). Don’t forget to record all measurements in Quantitative Data Section.
Part 3: Capturing your Flame to help you find the hottest part of the flame!
Hold an index card or piece of cardboard in the flame, in a vertical position just above the top of the barrel for on to 2 seconds. Remove the card immediately when it starts to scorch! (If it catches fire, throw it in the sink and try again, do not hold it in the flame as long). Place this in the Qualitative Data section of your lab report. Identify the hottest part of the flame on the card.
Next, stick a straight pin through a match a half of a centimeter below the head of the match.
Suspend the match in the barrel of the unlit burner. Turn on the gas and carefully light the burner (Figure 4). Write your results in the Qualitative Data section.
Figure 1: The Ideal LIT burner Figure 2: How to Orient the Burner/Beaker
Figure 3: Heating Water Figure 4: Pin/Match in LIT Burner
Qualitative Data:
Part 1:
Turning the barrel counterclockwise makes the flame more blue and incorporates more oxygen into the flame (Figure 5). Turning the barrel clockwise fully makes the flame more red because it takes away oxygen in the combustion of the gas.
Part 3:
When we turned on the heat, the match did not light (Figure 6). There is a flame surrounding the match, but it is not lit.
Figure 5: Turning the Barrel Figure 6: The Match is Unlit
Burnt Index Card:
The hottest point on the card is the inside portion of the outer ring of the burner.
Quantitative Data:
The smallest division on a thermometer is 1oC. This means that this thermometer can be read to 0.1oC.
Temperature of Water in a Beaker at Various Heights for 2 Minutes
Position
Starting Time
15s
30s
45s
60s
75s …show more content…
90s
105s
120s
A
23.2oC
26.1oC
27.5oC
32.2oC
35.1oC
37.0oC
40.2oC
48.2oC
49.4oC
B
25.0oC
28.5oC
29.5oC
32.2oC
35.8oC
38.0oC
40.1oC
41.1oC
44.0oC
C
24.5oC
25.0oC
26.1oC
29.1oC
32.2oC
34.9oC
37.5oC
39.2oC
42.0oC
D
24.9oC
26.8oC
28.1oC
29.9oC
31.4oC
33.2oC
34.1oC
38.1oC
39.1oC
Data Analysis:
The table and graph show the temperatures taken at different times for different positions on a Bunsen burner (Figure 7). Position A starts from the lowest temperature (296.4 K), and went up to the highest temperature (322.6 K). Position B starts from 298.2 K and goes up to 317.2 K. Position C starts at 297.7 K and goes up to 315.2 K. Position D (Figure 8) starts at 298.1 K and goes up to 312.3 K. This shows that Position A, or the base of the flame, was the most hot, Position B was the second most hot, Position C was the third most hot, and Position D was the least hot.
Position A is probably the most hot because there is less energy being lost from the flame to the glassware. In positions B, C and D, some of the heat energy could have easily been lost.
There is a bit of air in between the match and the gas, so the match is never touching the match, thus not lighting it on fire. If we would have left the match in the burner for a long period of time, the heat would have lit the match.
Figure 7: Positions for Part 2 Figure 8: Position D
Calculations:
I am converting Celsius to Kelvin. Celsius plus 273.15 is equal to the equivalent Kelvin value.
T(°C) + 273.15 = T(K)
Starting Temperature
A: 23.2oC + 273.15 = T(K) ; 296.35 K ; (Sig Figs) = 296.4 K
B: 25.0oC + 273.15 = T(K) ; 298.15 K ; (Sig Figs) = 298.2 K
C: 24.5oC + 273.15 = T(K) ; 297.65 K ; (Sig Figs) = 297.7 K
D: 24.9oC + 273.15 = T(K) ; 298.05 K ; (Sig Figs) = 298.1 K
15 Seconds
A: 26.1oC + 273.15 = T(K) ; 299.25 K ; (Sig Figs) = 299.3 K
B: 28.5oC + 273.15 = T(K) ; 301.65 K ; (Sig Figs) = 301.7 K
C: 25.0oC + 273.15 = T(K) ; 298.15 K ; (Sig Figs) = 298.2 K
D: 26.8oC + 273.15 = T(K) ; 299.95 K ; (Sig Figs) = 300.0 K
30 Seconds
A: 27.5oC + 273.15 = T(K) ; 300.65 K ; (Sig Figs) = 300.7 K
B: 29.5oC + 273.15 = T(K) ; 302.65 K ; (Sig Figs) = 302.7 K
C: 26.1oC + 273.15 = T(K) ; 299.25 K ; (Sig Figs) = 299.3 K
D: 28.1oC + 273.15 = T(K) ; 301.25 K ; (Sig Figs) = 301.3 K
45 Seconds
A: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
B: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
C: 29.1oC + 273.15 = T(K) ; 302.25 K ; (Sig Figs) = 302. 3 K
D: 29.9oC + 273.15 = T(K) ; 303.05 K ; (Sig Figs) = 303.1 K
60 Seconds
A: 35.1oC + 273.15 = T(K) ; 308.25 K ; (Sig Figs) = 308.3 K
B: 35.8oC + 273.15 = T(K) ; 308.95 K ; (Sig Figs) = 309.0 K
C: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
D: 31.4oC + 273.15 = T(K) ; 304.45 K ; (Sig Figs) = 304.5 K
75 Seconds
A: 37.0oC + 273.15 = T(K) ; 310.15 K ; (Sig Figs) = 310.2 K
B: 38.0oC + 273.15 = T(K) ; 311.15 K ; (Sig Figs) = 311.2 K
C: 34.9oC + 273.15 = T(K) ; 308.05 K ; (Sig Figs) = 308.1 K
D: 33.2oC + 273.15 = T(K) ; 306.35 K ; (Sig Figs) = 306.4 K
90 Seconds
A: 40.2oC + 273.15 = T(K) ; 313.35 K ; (Sig Figs) = 313.4 K
B: 40.1oC + 273.15 = T(K) ; 313.25 K ; (Sig Figs) = 313.3 K
C: 37.5oC + 273.15 = T(K) ; 310.65 K ; (Sig Figs) = 310.7 K
D: 34.1oC + 273.15 = T(K) ; 307.25 K ; (Sig Figs) = 307.3 K
105 Seconds
A: 48.2oC + 273.15 = T(K) ; 321.35 K ; (Sig Figs) = 321.4 K
B: 41.1oC + 273.15 = T(K) ; 314.25 K ; (Sig Figs) = 314.3 K
C: 39.2oC + 273.15 = T(K) ; 312.35 K ; (Sig Figs) = 312.4 K
D: 38.1oC + 273.15 = T(K) ; 311.25 K ; (Sig Figs) = 311.3 K
120 Seconds
A: 49.4oC + 273.15 = T(K) ; 322.55 K ; (Sig Figs) = 322.6 K
B: 44.0oC + 273.15 = T(K) ; 317.15 K ; (Sig Figs) = 317.2 K
C: 42.0oC + 273.15 = T(K) ; 315.15 K ; (Sig Figs) = 315.2 K
D: 39.1oC + 273.15 = T(K) ; 312.25 K ; (Sig Figs) = 312.3 K
Error Analysis:
The positioning of the Bunsen burner to the beaker is slightly subjective. We do not know if the amount of heat energy outputted by the Bunsen burner is the same (from trial to trial) (in Part 2). The beaker and the water was not the same temperature when we started and completed the experiments. We did not always put the index card in for two seconds, because some of them started to catch fire quickly.
Conclusion:
How should a Bunsen burner be lit and adjusted to attain a blue flame? What is the hottest part of a Bunsen burner flame? Is burning the gas a chemical or physical change? Is it endothermic or exothermic? The Bunsen burner should be lit by striking the match first, turning on the gas, igniting the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame. I predict that the hottest part of the Bunsen burner flame is the tip of the flame. The gas burning is a chemical change. It is exothermic. In this lab, we had three procedures. In the first experiment, we needed to figure out how to light a Bunsen burner. First, we cleared our area of anything flammable. Next, we plugged our hose into the hose outlet and gathered our materials. We opened the gas flow valve and lit the burner. By turning the gas valve in different directions, we achieved a blue flame.
In the second experiment, we set up a ring with a wire screen on top of the Bunsen burner. We positioned it so that it was close to the base of the flame. We heated 100 mL of water for two minutes and recorded the temperature every 15 seconds (and the starting temperature). We repeated this three more times, changing the position of the beaker to the flame.
In the third experiment, we burned an index card (Figure 10) by putting it at the top of the barrel for two seconds. We also stuck a straight pin through a match and suspended it in between the middle of the Bunsen burner. We turned on the gas and lit the Bunsen burner.
In our first experiment, after learning how to light the burner, we found that turning the barrel counterclockwise makes the flame more blue and incorporates more oxygen into the flame.
We also found that turning the barrel clockwise fully made the flame more red because it took away the oxygen in the reaction.
In our second experiment, we found that Position A, or the base of the flame, was the hottest (of the positions), Position B was the second most hot, Position C was the third most hot, and Position D was the least hot. Position A started from the lowest temperature (296.4 K), and went up to the highest temperature (322.6 K). Position B started from 298.2 K and went up to 317.2 K. Position C started at 297.7 K and heated up to 315.2 K. Position D (Figure 8) started at 298.1 K and went up to 312.3 K. Position A is probably the most hot because there is less energy being lost from the flame to the glassware. In positions B, C and D, some of the heat energy could have easily been lost.
In the third experiment, we found that the match did not light when we turned on the burner. There is a bit of air in between the match and the gas, so the match was never touching the match, thus not lighting it on fire. If we would have left the match in the burner for a long period of time, the heat would have lit the
match.
From these experiments, I learned that, to light a Bunsen burner, and achieve the best flame, it is best to strike the match first, turn on the gas, ignite the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame.
My hypothesis for the hottest part of the Bunsen burner is wrong. I thought that Position D would be the most hot, but it turned out to be the coldest. Position A, or the base of the flame, turned out to be the hottest. The hottest part of a Bunsen burner is the inner cone’s flame (Figure 11 &12).
The reaction of burning gas is a chemical exothermic reaction. A chemical reaction is a reaction that changes the identity of the substance. An exothermic reaction is a reaction that releases heat energy. I could feel the heat when the gas was being burned, and I did not smell gasoline coming from the fire. This means that there was a different product coming out of the reaction, showing that a chemical reaction occurred.
From this lab, I learned the skills necessary to safely handle a Bunsen burner. I also learned how to read a thermometer and adjust a Bunsen Burner’s flame. I will use these skills in other labs so I do not burn myself.
Figure 10: Burning the Card Figure 11: Bunsen Burner’s Flame Anatomy Figure 12: Hottest Part
Problems:
How should a Bunsen burner be lit and adjusted to attain a blue flame?
What is the hottest part of a Bunsen burner flame?
Is burning the gas a chemical or physical change? Is it endothermic or exothermic?
Hypothesis:
The Bunsen burner should be lit by striking the match first, turning on the gas, igniting the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame. I predict that the hottest part of the Bunsen burner flame is the tip of the flame. The gas burning is a chemical change. It is exothermic.
Background Information:
Often a chemist needs to heat materials. The Bunsen Burner is one of the most effective ways of doing this. Burners …show more content…
come in a variety of designs but operate on the principle of mixing gas with air to produce a hot flame. Bunsen burner’s have two areas for burning gas/air:: the primary, colored flame, and an outer, almost colorless, flame. A Bunsen burner mixes air with gas to produce a hot flame. A blue flame is the most desirable flame because it is the hottest and has the correct amount of oxygen for complete combustion. A red flame shows incomplete combustion and a lower temperature. Essentially, the the blue flame has the right amount of oxygen and the red flame is burning only the gas.
Materials:
Matches
Water
Pin
Index Card
Equipment
Bunsen Burner
Beaker
Thermometer
Ring Stand/Ring/Wire Sheet
Gas Hose
Parts of a Bunsen Burner:
A: Barrel - Where gas and air are mixed
B: Collar - Adjust the air intake
C: Air intake openings - air centers here
D: Gas intake tube - Gas enters burner from table source.
E: Gas Flow Valve - regulates flow of gas (can be controlled from table gas valve)
F: Base - Supports burner
Safety:
Remember to tie back your hair and make sure your clothes are not baggy. Be sure to keep your area free of loose paper and always have a person monitoring the burner. Remember that hot glass looks the same as cold glass.
Procedure:
Part 1: Lighting the Burner
First, connect the hose to the hose outlet. Clear the area of flammable objects (including clothing and your hair). Next, turn the barrel so that the air intake openings are closed, and open it three full turns. Open the gas flow valve on the table and light the burner. Adjust the barrel so that the flame is pale blue with a dark blue inner cone (Figure 1). What happens to the flame if the barrel is turned counter clockwise? (Place in Qualitative Data section) What happens to the flame if the barrel is turned clockwise fully (Place Qualitative Data section)?
Part 2: Finding the Hottest Part of the Flame
First, set up the support stand, ring, and wire screen as shown in the photos (Figure 2). Then, position the ring clamp so that the beaker is at the base of the flame. Put 100 mL of water into the beaker and record the starting temperature of the water on your data sheet. After that, heat the water for two minutes (Figure 3). Make sure to record the temperature of the water every 15 seconds. Finally, repeat this procedure for positions A, B, C, and D using fresh water each time (Figure 2). Don’t forget to record all measurements in Quantitative Data Section.
Part 3: Capturing your Flame to help you find the hottest part of the flame!
Hold an index card or piece of cardboard in the flame, in a vertical position just above the top of the barrel for on to 2 seconds. Remove the card immediately when it starts to scorch! (If it catches fire, throw it in the sink and try again, do not hold it in the flame as long). Place this in the Qualitative Data section of your lab report. Identify the hottest part of the flame on the card.
Next, stick a straight pin through a match a half of a centimeter below the head of the match.
Suspend the match in the barrel of the unlit burner. Turn on the gas and carefully light the burner (Figure 4). Write your results in the Qualitative Data section.
Figure 1: The Ideal LIT burner Figure 2: How to Orient the Burner/Beaker
Figure 3: Heating Water Figure 4: Pin/Match in LIT Burner
Qualitative Data:
Part 1:
Turning the barrel counterclockwise makes the flame more blue and incorporates more oxygen into the flame (Figure 5). Turning the barrel clockwise fully makes the flame more red because it takes away oxygen in the combustion of the gas.
Part 3:
When we turned on the heat, the match did not light (Figure 6). There is a flame surrounding the match, but it is not lit.
Figure 5: Turning the Barrel Figure 6: The Match is Unlit
Burnt Index Card:
The hottest point on the card is the inside portion of the outer ring of the burner.
Quantitative Data:
The smallest division on a thermometer is 1oC. This means that this thermometer can be read to 0.1oC.
Temperature of Water in a Beaker at Various Heights for 2 Minutes
Position
Starting Time
15s
30s
45s
60s
75s …show more content…
90s
105s
120s
A
23.2oC
26.1oC
27.5oC
32.2oC
35.1oC
37.0oC
40.2oC
48.2oC
49.4oC
B
25.0oC
28.5oC
29.5oC
32.2oC
35.8oC
38.0oC
40.1oC
41.1oC
44.0oC
C
24.5oC
25.0oC
26.1oC
29.1oC
32.2oC
34.9oC
37.5oC
39.2oC
42.0oC
D
24.9oC
26.8oC
28.1oC
29.9oC
31.4oC
33.2oC
34.1oC
38.1oC
39.1oC
Data Analysis:
The table and graph show the temperatures taken at different times for different positions on a Bunsen burner (Figure 7). Position A starts from the lowest temperature (296.4 K), and went up to the highest temperature (322.6 K). Position B starts from 298.2 K and goes up to 317.2 K. Position C starts at 297.7 K and goes up to 315.2 K. Position D (Figure 8) starts at 298.1 K and goes up to 312.3 K. This shows that Position A, or the base of the flame, was the most hot, Position B was the second most hot, Position C was the third most hot, and Position D was the least hot.
Position A is probably the most hot because there is less energy being lost from the flame to the glassware. In positions B, C and D, some of the heat energy could have easily been lost.
There is a bit of air in between the match and the gas, so the match is never touching the match, thus not lighting it on fire. If we would have left the match in the burner for a long period of time, the heat would have lit the match.
Figure 7: Positions for Part 2 Figure 8: Position D
Calculations:
I am converting Celsius to Kelvin. Celsius plus 273.15 is equal to the equivalent Kelvin value.
T(°C) + 273.15 = T(K)
Starting Temperature
A: 23.2oC + 273.15 = T(K) ; 296.35 K ; (Sig Figs) = 296.4 K
B: 25.0oC + 273.15 = T(K) ; 298.15 K ; (Sig Figs) = 298.2 K
C: 24.5oC + 273.15 = T(K) ; 297.65 K ; (Sig Figs) = 297.7 K
D: 24.9oC + 273.15 = T(K) ; 298.05 K ; (Sig Figs) = 298.1 K
15 Seconds
A: 26.1oC + 273.15 = T(K) ; 299.25 K ; (Sig Figs) = 299.3 K
B: 28.5oC + 273.15 = T(K) ; 301.65 K ; (Sig Figs) = 301.7 K
C: 25.0oC + 273.15 = T(K) ; 298.15 K ; (Sig Figs) = 298.2 K
D: 26.8oC + 273.15 = T(K) ; 299.95 K ; (Sig Figs) = 300.0 K
30 Seconds
A: 27.5oC + 273.15 = T(K) ; 300.65 K ; (Sig Figs) = 300.7 K
B: 29.5oC + 273.15 = T(K) ; 302.65 K ; (Sig Figs) = 302.7 K
C: 26.1oC + 273.15 = T(K) ; 299.25 K ; (Sig Figs) = 299.3 K
D: 28.1oC + 273.15 = T(K) ; 301.25 K ; (Sig Figs) = 301.3 K
45 Seconds
A: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
B: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
C: 29.1oC + 273.15 = T(K) ; 302.25 K ; (Sig Figs) = 302. 3 K
D: 29.9oC + 273.15 = T(K) ; 303.05 K ; (Sig Figs) = 303.1 K
60 Seconds
A: 35.1oC + 273.15 = T(K) ; 308.25 K ; (Sig Figs) = 308.3 K
B: 35.8oC + 273.15 = T(K) ; 308.95 K ; (Sig Figs) = 309.0 K
C: 32.2oC + 273.15 = T(K) ; 305.35 K ; (Sig Figs) = 305.4 K
D: 31.4oC + 273.15 = T(K) ; 304.45 K ; (Sig Figs) = 304.5 K
75 Seconds
A: 37.0oC + 273.15 = T(K) ; 310.15 K ; (Sig Figs) = 310.2 K
B: 38.0oC + 273.15 = T(K) ; 311.15 K ; (Sig Figs) = 311.2 K
C: 34.9oC + 273.15 = T(K) ; 308.05 K ; (Sig Figs) = 308.1 K
D: 33.2oC + 273.15 = T(K) ; 306.35 K ; (Sig Figs) = 306.4 K
90 Seconds
A: 40.2oC + 273.15 = T(K) ; 313.35 K ; (Sig Figs) = 313.4 K
B: 40.1oC + 273.15 = T(K) ; 313.25 K ; (Sig Figs) = 313.3 K
C: 37.5oC + 273.15 = T(K) ; 310.65 K ; (Sig Figs) = 310.7 K
D: 34.1oC + 273.15 = T(K) ; 307.25 K ; (Sig Figs) = 307.3 K
105 Seconds
A: 48.2oC + 273.15 = T(K) ; 321.35 K ; (Sig Figs) = 321.4 K
B: 41.1oC + 273.15 = T(K) ; 314.25 K ; (Sig Figs) = 314.3 K
C: 39.2oC + 273.15 = T(K) ; 312.35 K ; (Sig Figs) = 312.4 K
D: 38.1oC + 273.15 = T(K) ; 311.25 K ; (Sig Figs) = 311.3 K
120 Seconds
A: 49.4oC + 273.15 = T(K) ; 322.55 K ; (Sig Figs) = 322.6 K
B: 44.0oC + 273.15 = T(K) ; 317.15 K ; (Sig Figs) = 317.2 K
C: 42.0oC + 273.15 = T(K) ; 315.15 K ; (Sig Figs) = 315.2 K
D: 39.1oC + 273.15 = T(K) ; 312.25 K ; (Sig Figs) = 312.3 K
Error Analysis:
The positioning of the Bunsen burner to the beaker is slightly subjective. We do not know if the amount of heat energy outputted by the Bunsen burner is the same (from trial to trial) (in Part 2). The beaker and the water was not the same temperature when we started and completed the experiments. We did not always put the index card in for two seconds, because some of them started to catch fire quickly.
Conclusion:
How should a Bunsen burner be lit and adjusted to attain a blue flame? What is the hottest part of a Bunsen burner flame? Is burning the gas a chemical or physical change? Is it endothermic or exothermic? The Bunsen burner should be lit by striking the match first, turning on the gas, igniting the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame. I predict that the hottest part of the Bunsen burner flame is the tip of the flame. The gas burning is a chemical change. It is exothermic. In this lab, we had three procedures. In the first experiment, we needed to figure out how to light a Bunsen burner. First, we cleared our area of anything flammable. Next, we plugged our hose into the hose outlet and gathered our materials. We opened the gas flow valve and lit the burner. By turning the gas valve in different directions, we achieved a blue flame.
In the second experiment, we set up a ring with a wire screen on top of the Bunsen burner. We positioned it so that it was close to the base of the flame. We heated 100 mL of water for two minutes and recorded the temperature every 15 seconds (and the starting temperature). We repeated this three more times, changing the position of the beaker to the flame.
In the third experiment, we burned an index card (Figure 10) by putting it at the top of the barrel for two seconds. We also stuck a straight pin through a match and suspended it in between the middle of the Bunsen burner. We turned on the gas and lit the Bunsen burner.
In our first experiment, after learning how to light the burner, we found that turning the barrel counterclockwise makes the flame more blue and incorporates more oxygen into the flame.
We also found that turning the barrel clockwise fully made the flame more red because it took away the oxygen in the reaction.
In our second experiment, we found that Position A, or the base of the flame, was the hottest (of the positions), Position B was the second most hot, Position C was the third most hot, and Position D was the least hot. Position A started from the lowest temperature (296.4 K), and went up to the highest temperature (322.6 K). Position B started from 298.2 K and went up to 317.2 K. Position C started at 297.7 K and heated up to 315.2 K. Position D (Figure 8) started at 298.1 K and went up to 312.3 K. Position A is probably the most hot because there is less energy being lost from the flame to the glassware. In positions B, C and D, some of the heat energy could have easily been lost.
In the third experiment, we found that the match did not light when we turned on the burner. There is a bit of air in between the match and the gas, so the match was never touching the match, thus not lighting it on fire. If we would have left the match in the burner for a long period of time, the heat would have lit the
match.
From these experiments, I learned that, to light a Bunsen burner, and achieve the best flame, it is best to strike the match first, turn on the gas, ignite the gas, and adjusting the flame using the gas flow valve, the collar, and the table gas release to achieve a blue flame.
My hypothesis for the hottest part of the Bunsen burner is wrong. I thought that Position D would be the most hot, but it turned out to be the coldest. Position A, or the base of the flame, turned out to be the hottest. The hottest part of a Bunsen burner is the inner cone’s flame (Figure 11 &12).
The reaction of burning gas is a chemical exothermic reaction. A chemical reaction is a reaction that changes the identity of the substance. An exothermic reaction is a reaction that releases heat energy. I could feel the heat when the gas was being burned, and I did not smell gasoline coming from the fire. This means that there was a different product coming out of the reaction, showing that a chemical reaction occurred.
From this lab, I learned the skills necessary to safely handle a Bunsen burner. I also learned how to read a thermometer and adjust a Bunsen Burner’s flame. I will use these skills in other labs so I do not burn myself.
Figure 10: Burning the Card Figure 11: Bunsen Burner’s Flame Anatomy Figure 12: Hottest Part