Tag: extinguishing fire

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Questions Related to extinguishing fire

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Fire can be extinguished by spraying: 

  1. carbon dioxide

  2. carbon tetrachloride

  3. water

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fire can be extinguished by spraying, carbon dioxide, carbon tetrachloride or water.
Note:
Fire is extinguished by
(A) removing all combustible substance. Fuel is one of the requirements for producing fire. In the absence of fuel, combustion will not occur.
(B) cutting off the supply of air. Air (oxygen) is essential for combustion. In the absence of air, combustion will not occur.
(C) cooling the burning substance. This reduces the temperature below its ignition temperature. The fire will not spread.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

How will you distinguish between fire extinguishing action of water and $CO _2$? 

  1. Water helps to extinguish a fire in two ways: (1) It brings the temperature of the combustible material below its ignition temperature. (2) The water vapour formed due to the heat of fire cuts the supply of oxygen.

  2. Carbon dioxide is highly volatile. So, it immediately vaporises to cut off the supply of air. In the absence of supporter of combustion, fire is extinguished.
  3. Both $A$ and $B$

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both options A and B describe the difference between fire extinguishing action of water and $CO _2$.

  • Water helps to extinguish a fire in two ways: it cools the substance that undergoes combustion and brings the temperature of the combustible material below its ignition temperature. The water vapor formed due to the heat of fire surrounds the substance that undergoes combustion and cuts the supply of oxygen. 
  • Carbon dioxide is highly volatile and it is heavier than oxygen. So, it immediately vaporizes to cut off the supply of air. In the absence of supporter of combustion, fire is extinguished. Also, it does not damage electrical equipment.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

______ is the extinguisher used for inflammable material like petrol.

  1. Water
  2. $CO _2$

  3. Oil

  4. Dry powder
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Some Class-B fires (hydrocarbons, petroleums, and fuels on fire) cannot be efficiently controlled with water. $CO _2$ being heavier than oxygen covers the fire like a blanket. Hence, one of the important factor for fire is cut off and the fire is controlled.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

When paper is wrapped around an aluminium pipe ____________.

  1. ignition temperature reduces

  2. ignition temperature increase

  3. no change in ignition temperature

  4. the paper and aluminium catches fire very easily
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The ignition temperature of paper is lower compared to that of aluminium. When paper is wrapped around an aluminium pipe; the ignition temperature increases. That is why paper itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Which of the following is a constituent of foam type fire extinguisher?

  1. Dilute sulphuric acid

  2. Sodium carbonate

  3. Dilute hydrochloric acid

  4. All of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The foam type of fire extinguisher is also called as soda acid fire extinguisher. It consists of dilute sulphuric acid and sodium bicarbonate (soda). When it is released under high pressure in the form of foam, it covers the surface of fire and controls it by cutting off oxygen.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

The lowest temperature at which a substance catches fire?

  1. Flammable temperature

  2. Ignition temperature

  3. inflammable temperature

  4. None of above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ignition temperature is the lowest temperature at which a combustible substance when heated (as in a bath of molten metal) takes fire in air and continues to burn. It is also called also autogenous ignition temperature.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Inflammable substances have?

  1. Low ignition temperature

  2. Highest ignition temperature

  3. Moderate ignition temperature

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The substances which has a very low ignition temperature and can catch fire easily with a flame are called as inflammable substances. It is the ability of a substance to burn or ignite, causing fire or combustion. For eg; LPG, petrol etc. 

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Fire can be controlled by removing which of the following factor?

  1. Fuel

  2. Air

  3. Heat

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The three essential things required to control fire are fuel, heat and air. 

The air supplies oxygen and heat raises the temperature of the fuel beyond the ignition temperature. 
Fire can be controlled by removing any one of these factors. 


Hence, the correct option is $D$.


Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Which of the following is the most common fire extinguisher?

  1. Foam
  2. $CO _2$

  3. Water

  4. Dry powder
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The cheapest and most widely used fire extinguisher is water because it is easily available. But it is preferably used for class A fires. like fire in solids, wood, paper etc. Not suitable for Class B (Liquid) fires, or where electricity is involved. 


Hence, the correct answer is option $C$.

Multiple choice chemistry combustion extinguishing fire ways to control fire combustion, fuels and flame

Choose the correct statement from the following.


Forest fires are usually due to ______________.

  1. carelessness of humans

  2. heat of sun

  3. cutting of trees

  4. lightning strike
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Forest fires are usually due to campfires, burning of debris, littering of cigarettes or intentional acts of arson.


Hence, it is generally a result of careless activities of humans.

Hence the correct option is A.