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1.2 Let’s Play Safe1.3 Drawing Scientist Tools
1.4 Using the Bunsen Burner
Refer to page 5 of your notes
• The science laboratory can be a
dangerous place if you are not careful.
• There are certain rules that must be followed for your own safety and for the safety of everyone else in the room.
Refer to page 5 of your notes
Refer to page 4 of your notes
Activity Time (page 6)
Look carefully at the drawing below and find
all of the rules that are being broken in the
science laboratory
•Mixing chemicals without the teachers’ permission
Throwing rubbish / pouring chemicals into the washing basin
Eating in the science lab.
Loose papers close to the Bunsen flame
Smelling chemicals without teachers’ permission
Playing and pushing in the lab
Test tube pointing to own’s face and partner’s face
Pour substance down the sink
Hazard Symbols
Some of the chemicals that you use in the laboratory are potentially harmful. Hazard labels are used to label such chemicals to alert you to the type of hazards present.
This will be done in the lab.
Refer to page 7 of your notes
1. All laboratory apparatus should be drawn in outline only
and in their correct proportion.
2.Do NOT draw a 3-dimensional outlines for
laboratory apparatus.
3. Draw sectional diagrams of the apparatus that your teacher
shows you.
4. You may make use of the template of laboratory
apparatus sold in the school bookstores or included in your
mathematical set.
Laboratory Apparatus
Diagram
Purpose For transferring liquids into a flask
For supporting apparatus during experiments
For separating an insoluble solid from a liquid with the help of a piece of filter paper
Name thistle funnel retort stand filter funnel
Laboratory Apparatus
Diagram
Purpose For separating an experimental set-up from the outside environment
For supporting apparatus during heating
For containing chemicals or collecting liquids
Name bell jar tripod stand beaker
Laboratory Apparatus
Diagram
Purpose For containing chemicals when preparing gases if the process requires no heating
For containing or heating small amount of substances
For measuring a volume of liquid to an accuracy of 0.5 cm3
Name flat-bottomed flask test tube Measuring Cylinder
Laboratory Apparatus (pg7)
Diagram
Purpose For containing chemicals or collecting liquids
For containing water when collecting gases
For preparation of gases if the process requires heating
Name conical flask water trough round-bottomed flask
Laboratory Apparatus
Diagram
Purpose For evaporating a liquid from a solution
For collecting gases For heating solids directly over a flame
Name evaporating dish gas jar Crucible
Let’s try(page 7)Name the apparatus C – H in the following figure.
retort stand
thistle funnel
round-bottom flask
tripod
gas jar
Water trough
To raise the flame to a suitable height for burning
To enable the gas to rush out from the gas supply and to draw in air
Gas Tap To control the flow of gas to the Bunsen Burner
To control the amount of air entering the burner by opening or closing the air-holes
To control the air entering the Bunsen Burner
Refer to page 8 of your notes
The Bunsen Burner
We will covering the Bunsen burner in the lab.
Refer to page 8 of your notesTypes of flames
almost colourless zone of complete
combustion
Bunsen burner
dark zone of unburnt gas
blue zone of partial combustion
hottest partorange zone of incomplete combustion
A luminous flameA non-luminous flame
1. occurs when the air-holes are open, allowing air into the burner
2. blue3. burns steadily4. hotter than the luminous flame5. hottest part of the flame is just above the
tip of the blue zone.
1. occurs when the air-holes are closed and very little air is allowed to mix with the gas
2. carbon particles are deposited on apparatus
3. orange4. appears flickering and unsteady5. not very hot
Hottest
Refer to page 9 of your notes
STRIKEBACK1. occurs when there is too much
air entering air-hole2. instead of burning at the top of the
barrel, the gas burns at the jet3. when a strike back occurs, turn off
burner immediately
jet
http://www.youtube.com/watch?v=AWnSSvdMp5g
Refer to page 9 of your notes
HEATING LIQUID IN A BEAKER
1. put wire gauze on tripod stand2. put beaker of liquid on it3. light Bunsen burner and then push it under the tripod stand 4. turn off burner when the liquid reaches required temperature
Refer to page 9 of your notes
HEATING LIQUID IN A TEST-TUBE
1. hold test-tube with test-tube holder2. ensure that the mouth of the test-tube is pointing away from myself and others3. slant test-tube at an angle of about 45o and heat it in the hottest part of a
Bunsen flame4. move the test-tube through flame5. liquid to be heated should occupy no more than one-third test-tube
Let’s try(page 7)