PHYSICS FORM 1: TOPIC 2 - INTRODUCTION TO LABORATORY PRACTICE

TOPIC: 02 INTRODUCTION TO LABORATORY PRACTICE  

   

Laboratory  

• Is the special room that have been designed and equipped for carrying  out scientific experiments for the purposes of study or research 

 

• OR  Laboratory    Is a working room for scientists 

  

Examples of Laboratories are; 

● Clinical laboratory 

● Physics laboratory. 

● Biology laboratory. 

● Chemistry laboratory 

 

Laboratory rules - Are the guidelines to be followed in the laboratory in order to reduce risks of accidents  

 

The following are some of the physics laboratory rules. 

 

1. Don’t enter in the laboratory without permission from your teacher or laboratory assistance. 

2. Never fight in the laboratory 

3. Do not eat or drink in the laboratory 

4. Do not run or play in the laboratory 

5. Do not use laboratory container for drinking or storing food 

6. Wash your hands with soap before you leave the laboratory 

7. Don’t perform any experiment in the laboratory without permission from your teacher or laboratory assistance. 

8. All exits must be clear of abstraction/ obstacle. 

9. Any damages that may occur must be reported immediately to the laboratory attendant technician. 

10. All damaged or broken apparatus must be well deposited to a proper place. 

11. Never use free hand to hold hot objects. 

12. Replace immediately the cover or stopper of the particular chemical soon after use. 

13. After experiment, clean the bench and leave it dry and well arranged. 

14. All connections must be checked by laboratory attendant/technician in case of electrical experiments. 

 

Features of a Laboratory 

A good laboratory should have the following features  

• Water supply system  

• Drainage system  

• Electricity supply  

• Well illuminated  

• Well ventilated  

• Door open out ward 

• Gas supply  

 

Laboratory Apparatus  

 

• Is a special tool or instrument commonly used to carry out the experiments in the laboratory 

Laboratory Apparatus

Item	Uses
Measuring cylinder	For measuring volume of liquids
Thermometer	For measuring temperature of substances
Stop watch	To measure time
Micrometer screw gauge	For measuring diameter of a wire
Vernier caliper	For measuring depth, length, internal and external diameters of objects
A ruler	For measuring length
Relative density bottle	For measuring relative density
Microscope	For magnifying very small objects
Beaker	Used as container for chemicals and other liquids. Also can be used to estimate the volume of liquids
Spring balance	For measuring force in Newton
Slotted masses	Used for measuring for the quantity of matter.
Magnets	For demonstrating attraction and repulsion
Ball and ring apparatus	For demonstrating thermal expansion
Bar breaking apparatus	To show forces that can be exerted during thermal expansion and contraction
Tripod stand	For providing a platform for heating for stability
Wire gauze	For providing equal distribution of heat while burning
Bunsen burner	As source of heat
Retort stand	For holding/gripping materials
Triple beam balance	Measuring mass

Flasks	For holding liquids during experiment
Electronic balance	For measuring mass in more precise values

Laboratory Safety  

 

• Is the situation in which laboratory users can be  protected from danger, risk or injury  

 

      Laboratory Safety includes:-  

 

• Laboratory should be well ventilated and his door should open outward  

• Fire extinguishers should be fitted in an accessible position with using instruction  

• Laboratory floors should not have polished to avoid slippery  

• First aid kit must present in the laboratory  

• Cabinets and drawer must present for storing apparatus  

• All apparatus should have checked regularly to ensure they are safe to use  

• Emergence exit should present and easy to access and use  

 

First Aid  

• Is the immediate assistance given to a victim before getting professional medical help 

OR  

• Is an immediate care given to an injured person before she/he is taken to a nearby hospital for further medical treatment. 

Importance of First Aid  

• It helps to preserve life  

• It prevents the victim’s condition from becoming worse  

• It promotes recovery by bringing hope and encouragement to the victim  

• It helps to reduce pain and suffering  

• It prevents infection  

First Aid Kit  

• Is a small box used to store instruments and chemicals needed for first aid. 

OR 

• Is a small box containing items that are used to give help to a sick or injured person. 

• Usually labeled as “FIRST AID” and stored in a safe and easily accessible place  

 

 The following table summarizes the items which are found in the first Aid kit 

 

Item(s)	Uses
1.A pair of scissors	To cut adhesive tapes, bandages and gauze
2. Rolls of adhesive tape	To hold firmly into wounds, bandages , gauze and cotton wool.
3. Bandages and cotton wool	To clean and cover wounds.
4.Sterilized new razor blade	Used in treating fresh or old wounds
Item(s)	Uses
5. Sterilized gauze	To clean and cover wounds
6.Safety pin	To tighten clip bandages
7.One Jar petroleum jelly	To apply on burns
8. Iodine tincture	To clean fresh cuts and bruises
9.Antiseptic soap	To wash hand and wounds
10. Antibiotic solution	To clean wounds.
11.Painkillers	Relieving Relieving pain

Causes of Laboratory Accident  

1. Slippery floor,  

2. Incorrect use and handling of apparatus,  

3. Gas leakages from faulty gas taps,  

4. Fires,  

5. Improper arrangement of laboratory instruments and chemicals. 

6. Playing, fighting or quarreling in the laboratory. 

7. Deviating from instruction for using chemical reagents or laboratory equipment. 

8. Performing unauthorized experiment or deviating from instruction of experiment.

9. Insufficient personal protection when performing an experiment 

10. Improper handling of potentially dangerous chemicals. 

11. Ignoring laboratory rules. 

  

The following are the ways used to minimize accidents in the laboratory: 

• Through following laboratory rules and safety precaution. 

• By using protection wears before beginning any experiment. 

• Proper arrangement of laboratory instruments and chemicals. 

 

First Aid Procedure  

• Is the step by step process taken in order to help the victim when accident occurs 

 

The following procedures may be used:- 

  

(a) Electric Shock  

When dealing with a victim of electric shock, remember to take the following actions  

• Do not touch the victim who still in contact with electric current. 

• BREAK the contact by switching off the current at the switch or meter box if can be reached easily  

• If it is not possible to switch off the current, move the person from the current using a dry non-metallic object, for instance a piece of dry wooden plank or a bloom  

• If you suspect that the area has high voltage electricity, call for professional help immediately  

• If the victim is unconscious, check the breathing and pulse rate. If he or she has breathing problem, he prepared to resuscitate if necessary  

• Administer First Aid for shock, burns or other injuries sustained by the victim.

  

• Seek medical assistance  

 

(b) Cuts (Or Wounds)  

For a small cut or wound: 

• Wash your hands using soap and cleaning water.  

• Put on your gloves.  

• Wash your wounds using salty water and clean cloth.  

• Cover the wounds or cut with an adhesive bandage or plaster.  

 

For a large cut or wounds:  

• Let the victim lay under a shade or allow her to sit comfortably.  

• Wash your hands using soap and clean water.  

• Put on your gloves.  

• Prevent further blood loss by applying pressure over the wound using a folded but clean handkerchief or cloth.  

• Use another cloth to secure the first one in place.  

• Take the injured person to hospital.  

(c) Fainting  

• Fainting is the situation where by victim is weak and unable to stand. It is caused by too much heat and congestion  

 

Steps to Help a Victim  

• Take the person to a cool place or under a shade  

• Let him lie on his back with his legs raised higher than the head.  

• Loosen his clothes and ensure sufficient supply of air  

• Dip a clean handkerchief in water and press on his forehead.  

• Give him/her clean water to drink when he regains consciousness 

• If not, take the victim to the nearest hospital  

 

Fire  

• Is the state (process) of combustion that results into light, heat, smokes and flame  

Fire Triangle  

• Are the components needed to start a fire.  

These include  

a) Fuel  

b) Oxygen  

c) heat  

 

Causes of Laboratory Fire 

(a) Electrical faults  

(b) Smoking materials  

(c) Carelessness  

(d) Ignorance and negligence  

 

Basic Principles of Fire Prevention  

• No lighting of open fires near buildings 

 

• No smoking in prohibited areas  

• No interference with electrical installations  

• All electrical appliances must be switched off after use  

• All sources of heat should not be kept near the bench edge where they can easily be knocked down  

• All flammable substances should be locked up in drawers or cabinets  

 

Fire Extinguisher  

• Is the one in which is used to fight or stop fire to continue 

 

Types of Fire Extinguisher  

• Water extinguisher  

• Sand extinguisher  

• Fire Blanket extinguisher  

• Dry powder extinguisher  

• Carbon dioxide extinguisher  

• Foam extinguisher  

• Wet chemical extinguisher  

• ABC extinguisher  

 

Mechanism of fighting for Fire  

• Fire extinguisher stop fire by preventing one among of the fire components/fire triangle  

Classes of Fire  

• Fire are classified according to materials burnt; therefore, we have six classes of fire namely  

• Class A        

• Class B        

• Class C      

• Class D        

• Class E        

  

• Class F  

Fire class	Burning material	Suitable extinguisher
CLASS A	Organic solids (wood, paper plastics etc)	Water
CLASS B	Flammable liquids and greases  (Petrol, Paraffin and alcohol)	Dry Powder
CLASS C	Flammable gases (methane , LPG ----)	Dry powder
CLASS D	Combustible metals (Magnesium or sodium)	Dry powder
CLASS E	Electrical hazards (damaged electrical cables, switch boards)	Carbon dioxide
CLASS F	Cooking oils and fats (deep fat fryers)	Wet chemical

• NB:  There is NO one extinguisher type which works on all classes of fire 

  

Warning Signs  

Warning sign is the symbol established to ensure safety in the laboratory and in other fields like goods

 or commodities. This signs should have obeyed to avoid accidents, include the following  

• Toxic                   

  

• Irritant (harmful)   

           

• Flammable          

• Corrosive              

• Radio Active             

          

• Danger of electric shock    

• Fragile                    

• Explosive                   

        

• Careful     

• Flammable          

• Keep away from water     

     

• Oxidizing agent  

Toxic

• Toxic symbol means that a substance is dangerous and can cause death within a short time.  

• Toxic substances containing poisonous ingredients, examples of toxic substance is jik, mercury etc  

  

• Toxic substance enters the body through Ingestion (by eating and drinking), Inhalation (by breathing) ,by injection and Contact  

        Irritant (Harmful)  

• It means that a substance is dangerous and can affect our health for long time.   Examples are alcohol, paint, insecticide, tobacco, ammonia etc 

  

 Flammable  

• It means that the substance can catch fire easily.  

• For example gasoil, kerosene, petrol, butane, methane, spirit,  

  

     

  Oxidizing Agent  

• It means that the substance can speed up the rate of burning. 

• For example oxygen gas, chlorine gas, fluorine gas and hydrogen peroxide  

        

Corrosive 

• The symbol means that the substance causes gradual change when in contact with various materials.  

• For example, concentrated sulphuric acid, concentrated hydrochloric acid etc. 

  

   Radio Active  

• It means that the substance emits harmful radiations that penetrate the human body and cause damage. For Example uranium, plutonium etc  

  

   Danger of Electric Shock  

• It means that the substance has high voltage which you should not touch.

  

   

  • It means that the substance should be handled with care to prevent them from breaking. For example, glass etc.  

  

   Explosive  

• The symbol means that the substance can erupt (explode) easily. 

  

• Never store explosive material in glass container because when explode pieces of glass would fly all over and injure people 

 

 

   Careful  

• The symbol is the caution (advice), you need to be carefully  

  

   Keep Away from Water  

• Is the caution (advice) you have to keep items away from water? 

•   For example, computer, mobile phones, radio etc  

Scientific Investigation (scientific procedure) 

• Scientific method is a set of techniques used by scientists to investigate a problem/answer question.  

Steps of a Scientific Method  

The following are steps followed when carrying out a scientific investigation  

• Problem identification  

• Asking questions  

• Formulation a testable hypothesis 

 

• Performing an experiment  

• Data collection and analysis  

• Data interpretation  

• Data presentation  

• Drawing a conclusion  

 

Significance of the Scientific Procedure  

• It helps us to solve scientific problems  

• It helps us to gain new knowledge  

• It helps us to conduct project work  

• It helps us to carry out field study  

• It helps us to solve problems or answer scientific questions  

        

Exercise

1. Define the term laboratory. 

2. Describe the common features of a science laboratory. 

3. Explain why one should know the laboratory safety rules before entering or starting any activity in the Science Laboratory. 

4. Mention some of the rules which ensure safety in the Science Laboratory. 

5. What are warning signs? 

6. Mention types of laboratory 

7. State five classes of fire and their most appropriate fire extinguishers. 

8. Write true for correct and false for incorrect statements for each of the following: 

(a) You should move the victim of electric shock using a metallic object ------ 

(b) First Aid helps to preserve life --------

(c) Eating in the laboratory is prohibited ---------------- 

(d) Thermometers are used for measuring body temperatures ----

(e) A micrometer screw gauge is used to measure internal and external diameters of a test tube - 

9. Mention safety measures that protect your body from the dangers of an experiment you are doing. 

10. Draw the following apparatus and state their uses 

(a) Beaker

                               

(b) Thermometer  

                       

(c) Micrometer screw gauge   

(d) Measuring cylinder     

   

11. List down at least four accidents that are likely to occur in the science laboratory 

12. What do you understand by First Aid? 

13. What is the importance of first Aid? 

14. List ten (10) contents of the first Aid Kit. 

15. State the uses of the following instruments and chemicals in the First Aid Kit: 

(a) Petroleum jelly 

(b) Rolls of adhesive tape, plasters and bandages 

(c) Iodine tincture. 

Quantities	SI unit	Unit symbol
Length	Metre	m
Mass	Kilogram	kg
Time	Second	S
Electric current	Ampere	A
Temperature	Kelvin	K
Amount of substance	Mole	mol
Luminous intensity	Candela	Cd

(d) Antibiotic solution. 

(e) Methylated sprit. 

16. If an accident occurs in a laboratory, what first measures are taken to accident victim? 

17. What do you understand by the term scientific investigation? 

18. Define the term experiment as applied in scientific investigation.

 

19. What do you understand by the term hypothesis as applicable to scientific investigation?