Using a Bunsen BurnerA Bunsen burner can produce 3 different types of flames: The "coolest" flame is a yellow / orange color. It is called the safety flame. The medium flame, also called the blue flame or the invisible flame is difficult to see in a well-lit room. It is the most commonly used flame.
Air is admitted by rotating the barrel; gas is regulated with the needle valve. Insufficient air will cause a bright yellow, smoky flame; too much air will cause the flame to be noisy and blow itself out.
A hot flame is a nonluminous flame that releases little heat, light, and CO2. A cool flame is a nonluminous flame supplied with a reduced amount of fuel. The flame will be rich in fuel which produces a luminous flame. So, more air will produce a hot flame, but not too much oxygen!
STEPS TO LIGHT BUNSEN BURNER:
- Check connections to burner and desk outlet valve.
- Close needle valve and collar.
- Open desk outlet valve fully.
- Open needle valve 1/2 turn.
- Use the spark lighter to light the flame.
- Adjust collar and needle valve till you see a blue flame.
Strike back occurs when there is too much oxygen and create a green flame at the jet of the Bunsen Burner and creates a loud noise. This only occur when the air hole is fully open.
Actually, the hottest part of the candle flame is the blue part, at 1670 degrees F (1400 C.) That is where the flame has the most oxygen and you are getting complete combustion. The reddish part is the coolest part, about 1070 F (800C).
A blue flame colour means complete combustion. This indicates that the gas is being burned efficiently without any unburned and wasted gas. With complete combustion you get the maximum heat output from your gas and use less gas to generate heat with whatever appliance you are using.
Non-luminous flames are the ones that burn blue. These flames have access to as much oxygen as they could possibly use, so they can burn very efficiently. All of the carbon that gets used can be turned into CO2, so there's actually no soot.
The substances which vapourise during burning, give flames. For example, kerosene oil and molten wax rise through the wick and are vapourised during burning and form flames. Charcoal, on the other hand, does not vapourise and so does not produce a flame.
Because, flames consists of photons which can be defined as quantum of energies of varying freq. and wavelengths in the electromagnetic spectrum, blue has higher freq. than the red colour. Thus, energy is directly proportional to energy which makes the blue flame hotter than the red flame.
Flame colorants
| Color | Chemical |
|---|
| Green | Copper(II) sulfate, boric acid |
| Blue | Copper(I) chloride, butane |
| Violet | 3 parts potassium sulfate, 1 part potassium nitrate (saltpeter) |
| Blue/light violet | Potassium chloride |
When temperatures approach 2,400º F to 2,700º F, flames appear white. The color blue indicates a temperature even hotter than white. Blue flames usually appear at a temperature between 2,600º F and 3,000º F. Blue flames have more oxygen and get hotter because gases burn hotter than organic materials, such as wood.
If your gas hob flame is burning orange, then your worktop needs attention immediately. An orange or yellow flame means that it's releasing carbon monoxide as it burns which isn't what you want at all. A healthy flame will just be blue. It can be temporary and caused by particles in the air.
Oxygen (or air) and an ignition source are required for combustion to occur. Hydrogen burns with a pale blue flame that is nearly invisible in daylight. A pure hydrogen flame will not produce smoke. Hydrogen flames have low radiant heat.
Fully (or partly) open Closed This flame is still hot if you put your hand into it. To light the burner and when it is not being used to heat anything because is easy to see and will not readily set fire to clothing etc. This flame is unsuitable for heating as it coats surfaces with soot (carbon).
Blue: 1400-1650 °C (2600-3000 °F) Violet: 39400 °C (71000 °F)
If you have a yellow, orange, or red burner flame, this usually means that your burner is not receiving enough air for complete combustion. Besides wasted gas, higher energy bills, and more soot, the main danger of improper combustion is the increased amount of carbon monoxide (CO) produced by the combustion process.
Flames emits light and heat, so it seems impossible to make black fire. However, you actually can make black fire by controlling the wavelengths of absorbed and emitted light.
Using a Bunsen BurnerA Bunsen burner is one of the most widely used pieces of equipment in any chemistry laboratory. It is unique because it produces a hot, steady, and smokeless flame. The Bunsen burner is most often used to heat materials, but can also be used in sterilization and combustion.
The blue flame, can reach temperatures of approximately 500 oC and is almost invisible in a bright room. The next type of flame is characterised by a bright blue triangle in the centre of the flame and can reach temperatures of around 700oC. This flame makes a noise and is commonly known as the roaring blue flame.
Place the Bunsen burner away from any overhead shelving, equipment or light fixtures by at least 12 inches. Remove all papers, notebooks, combustible materials and excess chemicals from the area. Tie-back any long hair, dangling jewelry, or loose clothing.
The hottest part of the Bunsen flame, which is found just above the tip of the primary flame, reaches about 1,500 °C (2,700 °F). With too little air, the gas mixture will not burn completely and will form tiny carbon particles that are heated to glowing, making the flame luminous.
The Bunsen burner uses the combustion of methane (also called natural gas) and oxygen according to Equation 1 to produce heat. Less heat is produced during incomplete combustion. Mixing air with the gas before combustion ensures that enough oxygen will be available and complete combustion will occur.
White is an elusive fire color because the fuel that supports a flame burns with its own characteristic spectrum. But, with a little chemistry know-how, you can get white fire.
As things heat up and combustion becomes more complete, flames turn from red to orange, yellow and blue. And purple color is combination of red & blue color it means that blue fire is more hotter than purple fire. At hotter temperatures, the flame color moves into the blue-violet end of the visible spectrum.
Fun Fact: Hottest and Coolest FlamesThe hottest flame ever produced was at 4990° Celsius. This fire was formed using dicyanoacetylene as fuel and ozone as the oxidizer. Cool fire may also be made. For example, a flame around 120° Celsius may be formed using a regulated air-fuel mixture.
A wavering, yellow flame on a normal gas burner indicates that the burner is out of adjustment or the air inlet is restricted. As a result, the burner may be producing excessive amounts of CO. However, the flames in burners that use fuel oil should burn with a clear yellow or orange flame .
NO IT IS NOT SAFE…and read this: Don't Eat Hotdogs Cooked Over A Green Flame.. Went to my neighbors house last night after work and cooked a couple hotdogs over the fire. The copper wire burning turns the fire green.
If you have a fireplace in your home that you like to warm your hands over at a discreet distance, the flames providing the heat are roaring away at about 600 °C (1,100 °F). A bonfire stoked with charcoal and wood can get up to 1,100 °C (2,000 °F), as can a laboratory Bunsen burner.
You get a blue gas flame with a hydrocarbon gas when you have enough oxygen for complete combustion. When you do have sufficient oxygen, the gas flame appears blue because complete combustion creates enough energy to excite and ionize the gas molecules in the flame.
Blue flame is due to incandescence of very fine soot particles that are produced in the flame. With increasing oxygen supply, less black body-radiating soot is produced due to a more complete combustion and the reaction creates enough energy to excite and ionize gas molecules in the flame, leading to a blue appearance.
The bright orange of most wood flames is due to the presence of sodium, which, when heated, emits light strongly in the orange. The blue in wood flames comes from carbon and hydrogen, which emit in the blue and violet.
