Chemistry
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 and foam-type fire extinguishers?
Answer
Fire extinguishers are devices in which carbon dioxide is produced in different forms to be used as an extinguishing agent.
Liquid carbon dioxide is the substance used in the modern type of fire extinguishers.
Modern type of fire extinguisher is an improvement over the soda-acid and foam-type fire extinguishers in the following ways:
- Soda-acid fire extinguishers cannot be used for oil fire as the solution ejected being heavier than oil sinks below oil and does not work whereas modern type of fire extinguishers can be used to put out both oil-fed fires and electrical fires.
- Both the soda-acid and foam-type fire extinguishers solutions are prepared in water which conducts electricity. It might generate an electric shock leading to short circuit and another fire. But in modern type fire extinguishers, liquid carbon dioxide is used which does not conduct electricity. So, it can be used to put out electrical fires.
Related Questions
Give reasons for the following:
Solid carbon dioxide is used for the refrigeration of food.
(a) Name the chemicals required for the preparation of carbon dioxide in the laboratory.
(b) Write the balanced chemical equation for the preparation of CO2 in the laboratory.
(c) How will you collect CO2 gas in the laboratory?
(d) Draw a labelled diagram for the preparation of CO2 in the laboratory.
(e) Why is sulphuric acid not used for the preparation of carbon dioxide in the laboratory?
(f) Give a chemical test for carbon dioxide.
Explain the term greenhouse effect. What are its benefits? How is it harmful?
State three ways by which carbon dioxide gas is added into the atmosphere.