Home CHEMISTRY TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS...

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

62
0
TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

   QUESTIONS.

  1. Multiple choice.

   Choose the most correct answer.

  (i) What type of fire occurs in the vapour air-mixture over the surface of flammable liquids?

  A: class A

  B: class C

  C: class B

  D: class D

(ii) Combustion enables the following processes except _______

   A: washing

   B: heating

   C: smelting

   D: cooking

(iii)In order to start fire, the following components are needed

    A: fuel, oxygen and heat

    B: air and fuel

    C: heat and oxygen

    D: heat and combustible materials

(iv) Under normal condition, the percentage of oxygen in air is______

  A: 7.8       B: 21      C: 78           D: 2.1

(v) It is caused by combustible metals

   A: fire class A

   B: fire class B

   C: fire class C

   D: fire class D

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

(vi) A rapid chemical reaction that releases energy in form of light and noticeable heat is called __________

  A: ignition

  B: a reactant

  C: combustion

  D: heating

(vii) Occurs when combustible materials ignited and combine with oxygen.

  A: fire    B: heat     C: flame   D: soot

(viii) The process of extinguishing harmful fire

   A: fire starting

   B: fire outbreak

   C: fire fighting

   D: fire controlling

(ix) A portable fire extinguisher is always

    A: opened

    B: liquefied

    C: heavy

    D: in a metal container

(x) is formed on metal surface in presence of moisture and oxygen

  A: brown coating

  B: liquid

  C: soot

  D: red coating

  1. Matching items

   Match items in list A with responses in list B.

     LIST A.

(i) Turning of lime water into milky.

(ii) Tin plating

(iii) Oiling

(iv) Galvanization

(v) Silca gel

(vi)

(vii) Plastics

(viii) The gas that makes iron or steel rust

(ix) Change of dry salt into hydrated when it is exposed to the air.

(x) Rusting

    LIST  B.

A: Carbon dioxide

B: Oxygen

C: Formation or brown coat on the metal surface

D: Indicates that water is contained in air.

E: Indicates that, air contains carbon dioxide

F: Iron is coated with tin.

G: Tin is mixed with iron

H: Coating metal  that do not get rust

J: Prevent rust by absorbing moisture

K: Less expensive and never rust.

L: Air and moisture prevented to the metal surface.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. Fill in the blank spaces in the following statements.

(i) Iron,  _______and _______are necessary for rusting process.

(ii) Materials that catch fire and burn easily are said to be __________

(iii) The process of coating iron or steel with zink is known as _______

(iv) An APW fire extinguisher contains _______ pressurized by ____

(v) Combustion is a _________ process between substance and oxygen when flame is applied to them.

  1. Explain the methods which used to prevent rust.
  2. Why air is a mixture and not compound?
  3. How can we test the presence of the following substances in air?

    (a) Water

    (b) Carbon dioxide.

    (c) Oxygen.

  1. Define the following:-

    (a) Air

    (b) Combustion

    (c) Rusting

    (d) Rust

    (e) Fire

     (f) Fire fighting

  1. Which substances( conditions) are needed in order thefollowing processes to take place?

    (a) Rusting

    (b) Combustion

  1. Explain why water should not be used to extinguish fire class B and C?
  2. (a) Explain classes of fire and suitable extinguisher per each class.

     (b) Mention the chemical composition of each fire extinguisher suggested in (a) above.

  1. How rusting is prevented by:-

      (a) Oiling

      (b) Tin plating

      (c)  Painting

  1. Describe application of combustion and its importance.
  2. What should be done if fire caused by the following substances occur accidentaly.

   (a) clothes

   (b) petrol

   (c) electricity

   (d) cooking oil

  1. Atuganile was preparing food for her family, using a hot oil in a frying pan. Accidentally , the pan tipped over and a huge fire spread on her kitchen floor.

  (a) Which extinguisher would be appropriate for putting out fire?

  (b) Which extinguisher would be dangerous to use so as to put out fire?

  1. Outline components of air.

       ANSWERS.

  1. (i) C(vi) C

   (ii)  A               (vii) A

   (iii) A              (viii) C

   (iv) B              (ix) D

   (v)  D              (x) A

  1. (i) oxygen, water

   (ii) flammable

  (iii) galvanization

  (iv) air, water

   (v) burning

  1. (i)E                (vi) _

   (ii)  F                (vii) K

   (iii)  L               (viii) B

   (iv) H                (ix) D

   (v) J                 (x) C

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. (i) oxygen, water

   (ii) flammable

   (iii) galvanization

   (iv) air, pressure

   (v) burning

  1. The following methods applied to prevent rust

   (i) Painting

Paint when introduce on iron/steel prevent

iron/steel to react with water and air.

  (ii) Oiling

Oil when introduce on iron/steel prevent iron/steel to contact with water and air.

  (iii) Galvanization

  Galvanization is the process of mix iron/steel with metal that does not rusting.

When iron/steel mix with metal that does not rusting tend to prevent an iron/steel from rusting. Example Iron sheets are galvanized with zinc

   (iv) Anodizing

   Iron is joined to reactive metals (e.g. Magnesium) by wire. Examples

  • Bridges are anodized to protect it from rusting
  • pipelines are anodized to protect it from rusting

(v) Tin plating

    plating is the coating of iron/steel with tin (metal) that does not rust.

When iron/steel mix with metal that does not rusting tend to prevent an iron/steel from rusting.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

   (vi) Use of silica gel

    silica gel is a substance in the form of grains and absorbs moisture.

Example

  • silica gel bags put inside cameral parts which made from iron/steel to prevent rusting

Use of plastic

Uses of plastics tend to avoid cost of damage parts or instruments and household made from rusting.

  1. Air is a mixture due to the following reasons

   (i) Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air(physical means)

  (ii) It shows the properties of each  gas present in the atmosphere.

For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion.

   (iii) Air does not have a fixed formula.

   (iv) Air has a variable composition because air at different places contains different amount of gases.

   (v) Heat or Light energy is neither absorbed nor released when  air is prepared physically by mixing required amount of gases .

  (vi) Mixture does have fixed boiling Point like air. It holds good in case of liquid air.

  1. (a) We can test the presence of water in air by exposing white anhydrous copper (II) sulphate. White copper two sulphate turns blue after absorbing atmospheric water.

   (b) We can test the presence of carbon dioxide in air by exposing lime water on the watch glass to the air. After few days lime water turns milky is carbon dioxide is contained in the air.

   (c) Copper is used to test if oxygen is present in air. If it is exposed to the air it turn black from brown to show that oxygen is present in air.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. (a) Air

               Is a mixture of different gases.

     (b) Combustion

            Is a burning of the substance in presence of air (oxygen)

       (c) Rusting

              Is a process forming reddish brown coat on metals.

      (d) Rust

             Is a reddish brown coating on iron or steel caused by chemical reaction between iron(steel), water and oxygen.

      (e) Fire

           Is a collection of burning gases that give out heat and light.

    (f) Fire fighting

          is a process of extinguishing harmful fire

  1. (a) Conditions needed for rusting process include presence of

     (i) iron or steel

     (ii) water(moisture)

     (iii) oxygen(air)

   (b) Conditions needed for combustion process include presence of:-

      (i) fuel (combustible materials)

      (ii) heat

      (iii) oxygen (air)

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. – Water should not be used to extinguish fire class B because it is denser than liquid fuel such that it sinks down and leave the oil burning at the top this causes spreading of the fire.

    -For the fire class C water creates a shock hazard.

  1. (a) We have six classes of fire, which are fire class A, B, C, D, Eand F.
  • Fire class A

      Is a type of fire caused by solid solid combustible materials such as wood, plastics and papers.

  -appropriate extinguisher for this type of fire is water and any portable extinguisher except carbon dioxide.

  • Fire class B

    Is a type of fire caused by flammable liquids. Such as petrol, alcohol and kerosene.

  -it is extinguished by fire blanket if it is small and dry powder, foam or carbon dioxide if it is large.

  • Fire class C

       Is a type of fire which caused by flammable gases. Such as butane and propane.

      -its extinguishers are dry powder extinguisher and carbon dioxide

  • Fire class D

        Is a type of fire which caused by combustible metals. Such as magnesium, sodium and lithium usually when they are in powdered form.

    – appropriate extinguisher for this type of fire are dry powder extinguisher and foam extinguisher.

  • Fire class E

     Is a type of fire which caused by electrical equipment.

     -it is extinguished by carbon dioxide or dry powder extinguisher.

      Is a fire that caused by cooking appliances with oil and fat at high temperature.

   -it is extinguished by wet chemical extinguisher while the electric main power is switched off.

  1. (a) Oil avoid rusting by preventing water and oxygen to the metal.

       (b) Tin is a metal which does not rust, if it is coated on iron or steel no rusting of iron or steel can take place.

       (c) Paints consist of material non-reactive metal(zinc). They avoid reaction between painted iron or steel against oxygen and water.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. Application of combustion is described as follows.
  • it is applied  in cooking

     Fuel burnt so as to get heat energy which is specific for cooking.

  • it is applied in cleaning.

    It enables burning of wastes.

  • it is applied in heating.

    Fuel burn burnt so as to produce energy which is specific for heating.

  • it is applied in engine machines.

      Fuel is burnt so as to produce energy that run machine.

  • it is applied in welding and smelting.

        Fuel is burnt to produce a very hot flame which is specific for welding and smelting.

  • it is applied in lighting.

    Fuel is burnt to produce a flame which is specific for  giving light.

  NB:

-fuel is any substance that when burn energy is produced usually in form of heat and light.

     -flame is a visible gaseous part of fire.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. Immediately, fire should be put off by using appropriate extinguishers as follows:-

   (a) Fire caused by clothes is a fire class A. It should be extinguished by water.

   (b) Fire caused by petrol is fire class B. It should be extinguished by either fire blanket or sand if it is small, if it is large a dry powder, foam or carbon dioxide should be used.

  (c) Fire caused by electricity is a fire class E. It should be extinguished by carbon dioxide..

  (d) Fire caused by cooking oil is a fire class F. It should be extinguished by a wet chemical extinguisher.

TOPIC 6 : AIR COMBUSTION RUSTING AND FIRE FIGHTING QUESTIONS WITH ANSWERS ~ CHEMISTRY FORM 1

  1. (a) Wet chemical extinguisher

      (b) Water

  1. Air is composed with the following.

     -carbon dioxide (0.03%)

     -oxygen (21%)

     -water vapour (0-4%)

     -nitrogen (78%)

     -noble gases (0.94)

LEAVE A REPLY

Please enter your comment!
Please enter your name here