Advertisements
Advertisements
प्रश्न
People usually keep angithi/burning coal in their closed rooms during winter season. Why is it advised to keep the door open?
उत्तर
When coal burns in air, it produces carbon dioxide which is non-poisonous. But, when angithi or coal burns in a closed room, the air or oxygen cannot enter the room.
So, in the incomplete supply of oxygen, coal burns to produce carbon monoxide which is highly poisonous gas. It causes suffocation in a closed room. So, door and windows should be open.
APPEARS IN
संबंधित प्रश्न
Give reasons.
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
True or False – If False give the correct answer
Oxygen is necessary for combustion
Some words (underlined) in the following sentence is jumbled up. Write them in their correct form.
Slaags is a non-combustible material.
Match the items of Column A with the items of Column B.
| Column A | Column B |
| (a) Oxides of sulphur and nitrogen | (i) fire extinguisher |
| (b) CNG | (ii) incomplete combustion of coal |
| (c) Oxygen | (iii) very low ignition temperature |
| (d) inflammable substance | (iv) acid rain |
| (e) carbon dioxide | (v) necessary for combustion |
| (f) carbon monoxide | (vi) fuel for automobiles |
Complete the crossword with the help of the clues.
Across
1. Non-metal which catches fire if exposed to air. (10)
3. The lowest temperature at which a substance catches fire is called its ______ temperature. (8)
5. The most common fire extinguisher. (5)
Down
2. A chemical process in which a substance reacts with oxygen to give off heat. (10)
4. Petrol is used as a ______ in automobiles. (4)
6. It is as hard as stone and black in colour. (4)
Any reaction that involves reaction with oxygen is called reaction ______.
Complete the oxidation reaction.
CH4+2O2 → ______+______+Heat energy.
What do you mean by inflammable substance?
Fill in the blanks using the word given in the box.
| ignition | petrol | combustion | calorific value | combustible | combustible |
The lowest temperature at which a substance catches fire is called its ______ temperature.
Fill in the blanks using the words given in the box.
| ignition | petrol | combustion | calorific value | combustible | combustible |
Ignition temperature of ______ is lower than that of wood.
