Question

plz make a test for class 8
chapter :- 6 combustion and flame....​

Answer 1

Answer:

W

e use different kinds of fuel for

various purposes at home, in

industry and for running

automobiles. Can you name a few fuels

used in our homes? Name a few fuels

used in trade and industry. What fuels

are used for running automobiles? Your

list will contain fuels like cowdung,

wood, coal, charcoal, petrol, diesel,

compressed natural gas (CNG), etc.

You are familiar with the burning of a

candle. What is the difference between the

burning of a candle and the burning of a

fuel like coal? May be you were able to

guess right: candle burns with a flame

whereas coal does not. Similarly, you will

find many other materials burning

without a flame. Let us study the chemical

process of burning and the types of flame

produced during this process.

6.1 What is Combustion?

Recall the activity of burning of

magnesium ribbon performed in

Class VII. We learnt that magnesium

burns to form magnesium oxide and

produces heat and light (Fig. 6.1).

We can perform a similar activity with

a piece of charcoal. Hold the piece with

a pair of tongs and bring it near the

flame of a candle or a Bunsen burner.

What do you observe?

We find that charcoal burns in air.

We know that coal, too, burns in air

producing carbon dioxide, heat and