Combustion and Flame Class 8 Worksheet with Solved in Pdf
Combustion and Flame Class 8 Worksheet: In this page we have included Combustion and Flame Chapter from Grade 8 Worksheet with solution.
1.) Fill in the blanks.
A.) Magnesium burns to form magnesium oxide and produces heat and light.
B.) The substance which burn in air are called combustible.
C.) The unit of fuel is kilo joule per kg.
D.) Carbon dioxide is stored in liquid form in the cylinders.
E.) Fuel may be solid, liquid or gas.
F.) Phosphorus burn in air at room temperature.
G.) Cutting of trees leads to deforestation.
2.) Define the following.
A.) What is combustion?
Answer:- A chemical process in which a substance reacts with oxygen to give off heat is called combustion.
B.) Define ignition temperature.
Answer:- The lowest temperature at which a substance catches fire is called it's ignition temperature.
C.) Calorific value.
Answer:- The amount of heat energy produced on complete combustion of 1kg of fuel is called as calorific value.
D.) Define global warming.
Answer:- Increase in temperature of Earth's atmosphere is called global warming.
E.) What are three different zones of flame.
Answer:- The three different zones of flame are dark zone, luminous zone and non – luminous zone.
3.) Answer in brief.
A.) Explain acid rain.
Answer:- a. Burning of coal and diesel releases sulphur dioxide gas.
b.) It is an extremely suffocating and corrosive gas.
c.) Oxides of sulphur and nitrogen dissolve in rain water and form acids. Such rain is called as
acid rain.
d.) It is very harmful for crops, buildings and soil.
B.) Define combustion and types of combustion in brief.
Answer:- Combustion:- A chemical process in which a substance reacts with oxygen to give off heat is called combustion.
There are two types of combustion:-
a.) Rapid combustion: – Gas burns rapidly and produces heat and light is known as rapid combustion.
b.) Spontaneous combustion:- A material suddenly bursts into flames is called as spontaneous
combustion.
C.) Inflammable substances with example.
Answer:- The substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances.
Example of inflammable substances are petrol, alcohol, Liquefied Petroleum Gas (LPG) etc.
4.) True or false.
A.) Incomplete combustion of fuel gives poisonous carbon dioxide.
Answer:- True.
B.) Air is commonly used to control fires.
Answer:- False.
C.) Inflammable substances have high ignition temperature.
Answer:- False.
D.) Rise in temperature of atmosphere causes global warming.
Answer:- True.
E.) Carbon dioxide is best fire extinguisher.
Answer:- True.
Also See: Class 8 Science Worksheets