1. Bunsen burner
External View

2. Bunsen burner Air-hole: to allow air to enter the burner
Barrel: to raise the flame to a suitable height for burning or heating
Jet: to enable the gas to rush out of the gas supply and to draw in air
Collar: to regulate the amount of air entering the burner through the air-hole
Base: to support the burner so that it will not topple
Gas tap: to control the flow of gas to the Bunsen burner

3. Bunsen burner
Internal View

4. Lighting the Bunsen burner
1. Close the air-hole.
2. Put the gas lighter at the top of the barrel.
3. Turn on the gas tap. 4. Strike the lighter to get a luminous flame.

5. A Non-luminous Flame almost colourless zone of complete combustion
hottest part
blue zone of partial combustion
dark zone of unburnt gas
Bunsen burner

6. Non-Luminous Flame
occurs when the air-hole is open, allowing sufficient air into the burner
Blue
steady
very hot
hottest part of the flame is just above the tip of the blue zone

7. A Luminous Flame Bunsen burner orange zone of incomplete combustion
almost colourless zone of complete combustion
blue zone of partial combustion
dark zone of unburnt gas
Bunsen burner

8. Luminous Flame
occurs when the air-hole is closed and very little air is allowed to mix with the gas
Soot is deposited on apparatus
orange
appears flickering and unsteady
not very hot

9. Strike Back
flame at jet

10. Strike Back occurs when there is too much air entering air-hole
instead of burning at the top of the barrel, the gas burns at the jet
when a strike back
occurs, turn off burner immediately

11. Heating a Liquid in a Beaker
put wire gauze (gauze mat) on tripod stand
put beaker of liquid on it
light Bunsen burner and then push it under the tripod stand
turn off burner when the liquid reaches required temperature

12. Heating a Liquid in a Test tube
hold test tube with test tube holder
ensure that the mouth of the test-tube is pointing away from myself and others
slant test-tube at an angle of about 45O and heat it in the hottest part of a Bunsen flame
move the test-tube through flame
liquid to be heated should occupy no more than one-third test-tube