Presentation on theme: "Bunsen Burner Introducing Science In this chapter, you will learn: l What is a Bunsen burner. l How to use the Bunsen burner. l Heating substances with."— Presentation transcript:
Bunsen Burner Introducing Science
In this chapter, you will learn: l What is a Bunsen burner. l How to use the Bunsen burner. l Heating substances with a Bunsen burner. l Find out which flame is hotter.
A Bunsen Burner The first Bunsen burner Outer core Inner core Burner tube Stopcock Collar
Robert Bunsen l We heat things with a Bunsen burner ( 本生 燈 ) in the laboratory. l Robert Bunsen, a German chemist, invented this apparatus in 1855.
A Bunsen Burner
What are the parts of a Bunsen burner? Label the diagram using these words. air hole chimney collar tubing gas tap chimney air hole collar tubing gas tap
How do we use a Bunsen burner? 1.Join the burner to a gas tap.
How do we use a Bunsen burner? 2.Close the air hole.
How do we use a Bunsen burner? 3.Light a match and hold it over the chimney. Turn on the gas tap.
The Bunsen flame I l What will be the colour of the flame when the air hole is closed? This is a luminous flame.
The Bunsen flame II l Open the air hole slowly. l What will be the colour of the flame when the air hole is opened? This is a non-luminous flame.
Check point Use suitable words to fill in the blanks. l The non-luminous flame is (a) in colour. l The luminous flame is (b) in colour. l The (c) flame is easier to see. (a)yellow (b)blue (c)luminous
Flame I l with air hole CLOSED l yellow in colour l luminous Flame II l with air hole OPENED l blue in colour l non-luminous Which kind of flame is hotter? ? ?
How to know which flame is hotter? l To contact the flame with your hand? l To measure the temperature by a thermometer? X X l To compare the time taken to make the water boiled ?
How to heat an object? (1) The apparatus used in the procedure of heating: What are these? Tripod Bunsen Burner Wire gauze Beaker
How to heat an object? (2) 1.Prepare a Bunsen Burner 2. Put a tripod over the Bunsen Burner 3 Place a wire gauze onto the tripod
How to heat an object? (3) 4. Put a beaker onto the wire gauze 5. Then add water into the beaker
Measuring the time taken to boil a certain amount of water l Fill a beaker with 50 cm 3 of tap water l Set up the apparatus as shown in the diagram l Heat the water with a flame of Bunsen Burner until it boils l Use stop-watch to find out the time taken Stop-watch
Experiments to compare which flame is hotter Experiment 1 l with the air hole of Bunsen Burner CLOSED yellow flame Experiment 2 l with the air hole of Bunsen Burner OPENED blue flame
Experiment 1 (a) À Light a Bunsen Burner with the air hole closed Á Light a match and hold it over the chimney. Â Turn on the gas tap
Experiment 1 (b) Ã Put a beaker of water with 50 cm 3 of tap water onto the tripod Ä Heat the water until it boil Å Record the time needed by using Stop-watch
Experiment 2 (a) À Light a Bunsen Burner with the air hole opened Á Light a match and hold it over the chimney. Â Turn on the gas tap
Experiment 2 (b) Ã Put a beaker of water with 50 cm 3 of tap water onto the tripod Ä Heat the water until it boil Å Record the time needed by using stop- watch
Result of the experiments 1. Which flame make the water boiled first? l Yellow or blue flame? Ans: Blue flame 2. Which flame is hotter? Ans: Blue flame
Conclusion l So, Blue flame is better for heating
Practical exercises l Do you know how to use Bunsen Burner? l Do you know how to boil water? Do the experiment yourself NOW!