Fire Extinguisher

Q.

Which is the best fire extinguisher for fires involving electrical equipment and inflammable materials like petrol ?

Q. Acid rain mainly contains

1. Hydrochloric acid
2. Acetic acid
3. Sulphuric acid
4. Nitric acid

Q.

Explain how, carbon dioxide is able to control fires.

Q.

How does water help in extinguishing fire?

1. Water cools the combustible material so that its temperature is brought below the ignition temperature

2. The water heats the combustible material so that its temperature is brought below the ignition temperature

3. Water cools the combustible material so that its temperature is brought above the ignition temperature

4. None of these

Q. Question 5 (a)
Give reason.
Water is not used to control fires involving electrical equipment.

Q.

Explain foam-type fire extinguisher and its uses.

Q.

What is a fire extinguisher? What is the substance used in the modern type of fire extinguishers? How is it an improvement over the soda acid-type and the foam-type fire extinguishers?

Q. When clothes of a person catches fire, a blanket is used to extinguish it.

1. True
2. False

Q. What is the difference between ignition and combustion

Q.

Name the most common fire extinguisher.

Q. Which among the following is used in a fire extinguisher?

1. Hydrogen
2. Nitrogen
3. Carbon dioxide
4. Oxygen

Q.

Water works as a fire extinguisher by removing

1. Source of combustible substance.

2. Heat

3. Oxygen

4. Heat and Oxygen

Q.

When we burn a candle it's colour formed is yellow and orange why not in gas stove

Q.

What fire extinguisher contains?

Q.

Carbon dioxide is heavier than air.

1. True
2. False

Q. What are the necessary conditions for combustion to take place?

1. Presence of a combustible substance
2. Medium for combustion
3. Presence of carbon dioxide
4. Presence of a combustible substance and a medium for combustion

Q. Water can be used as an extinguisher when electrical equipments are on fire.

1. True
2. False

Q.

When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.

(a) Name the substance X.

(b) How does this substance extinguish the fire ?

(c) Name another susbtance which behaves like X.

Q.

Which of the following statement is not correct about carbon dioxide acting as a fire extinguisher for electrical fires ?

(a) it is heavier than air

(b) it is lighter than air

(c) it is not combustible

(d) it does not support combustion

Q. Which of the following is the best extinguisher for flammable materials?

1. Water
2. Sulphur dioxide
3. Carbon dioxide.
4. Carbon monoxide.

Q. ____ damage(s) the ozone layer of the atmosphere.

1. Helium
2. Chlorofluorocarbons
3. Oxides of nitrogen and sulphur
4. Hydrogen gas

Q.

A lot of dry powder of one of the following chemicals can be released over a fire to extinguish it. This chemical is :

(a) plaster of Paris

(b) baking soda

(c) washing soda

(d) bitumen

Q.

Why only blue colored flame indicates complete combustion why not green or any other colours?

Q.

___ is used in the preparation of washing soda, baking powder and urea.

1. Carbon dioxide

2. Oxygen

3. Carbon monoxide

4. Hydrogen

Q. Water cannot be used to put out fire on:

1. Paper
2. Fabric
3. Wood
4. Fuse box

Q. Identify the name of the process(es) that is used to obtain pure water.

1. Filtration
2. Chlorination
3. Boiling
4. Distillation

Q. Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.​
(a) How will she find the nature of the gas ?
(b) Write down word equations of all the reactions taking place in this process

Q. Statement I: Fire can be stopped by cutting off the oxygen supply.
Statement II: A substance cannot catch fire in the absence of oxygen.

1. Only statement I is true
2. Only statement II is true
3. Both statements are true
4. Both statements are false

Q. What is flame. When it is produced. What are the chemical reactions happening

Q. Give reason.
Water is not used to control fires involving electrical equipment.