Bunsen burner External View

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

Bunsen burner Internal View

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.

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

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

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

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

Strike Back flame at jet

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

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

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