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)