Fuels, Combustion and Flame Worksheet-10

Fuels, Combustion and Flame Worksheet-10

1. Why is more care needed to store kerosene than coal?

(a) Kerosene is a fuel while coal is not

(b) Coal is a fuel while kerosene is not

(c) Kerosene has a lower ignition temperature than coal

(d) Coal has a lower ignition temperature than kerosene

2. Select the incorrect statement.

(a) Insufficient supply of oxygen results in complete combustion.

(b) Insufficient supply of oxygen results in incomplete combustion

(c) Sufficient supply of oxygen results in complete combustion

3. The flame of a Bunsen burner is _____ when the air hole is open and _____ when the air hole is closed.

(a) Blue, green                              (b) Yellow, blue

(c) Yellow, green                          (d) Blue, yellow

4. Sleeping in a closed room with burning angeethi can prove to be fatal, because

(a) Coal is a poisonous substance

(b) Poisonous gas, carbon monoxide, is produced due to the incomplete combustion of coal

(c) Burning of coal in a closed room evolves carbon dioxide and water vapour, which are harmful

(d) None of these

5. Which amongst the following is the cleanest fuel?

(a) CNG             (b) Charcoal     (c) Diesel           (d) Petrol

6. Which of the following are requirements for producing fire?

(a) Oxygen and heat                    (b) Fuel and oxygen

(c) Fuel, oxygen and heat           (d) Fuel and heat

7. Mark the correct statement.

(a) Different substances catch fire at the same temperature

(b) Different substances catch fire at different temperatures

(c) Same substance can catch fire at different temperatures

(d) None of these

8. Match column I and column II and select the correct option from the codes given below.

(a) (A)-(I); (B)-(II); (C)-(IV); (D)-(III)

(b) (A)-(III); (B)-(II); (C)-(I); (D)-(IV)

(c) (A)-(IV); (B)-(III); (C)-(I); (D)-(II)

(d) (A)-(II); (B)-(III); (C)-(I); (D)-(IV)

9. When steam is passed over red hot coke, a mixture of carbon monoxide and hydrogen is obtained. It is known as

(a) Natural gas                              (b) Water gas

(c) Producer gas                           (d) Bio gas

10. A spoon is kept in contact with ice cubes for sometime. Later, the same spoon was held over the flame of a small candle. The figure shows the observation. What do you infer from the given figure?

(a) Spoon is an inflammable substance

(b) Burning of candle is a spontaneous process

(c) CO₂ is a product of combustion

(d) Water vapour is a product of combustion

11. The amount of energy released on complete burning of 1 kg of a substance is called

(a) Heat capacity                          (b) Calorific value

(c) Ignition value                          (d) Combustibility

12. Arrange the following in terms of their increasing fuel efficiency

(a) wood < coal < Diesel < LPG

(b) coal < wood < Diesel < LPG

(c) LPG < Diesel < coal < wood

(d) Diesel < LPG < coal < wood

13. Which of the following statements is correct?

(a) Any substance that can burn is an inflammable substance

(b) Spontaneous combustion starts at room temperature

(c) During an explosion, a large amount of acid is produced

(d) Water is useful in putting out all fires

14. When combustion occurs unburnt, carbon particles are produced.These particles are harmful, as they cause

(a) Respiratory problems           (b) Digestion problems

(c) Heart problems                      (d) Skin problems

15. Which of the following gases is responsible for causing green house effect and global warming?

(a) SO₂               (b) SO₃               (c) CO                 (d) CO₂

16. When a hydrocarbon fuel is burnt in a sufficient supply of air, _____ and _____ are produced.

(a) CO, CO₂                                   (b) CO₂, H₂O vapours

(c) CO, H₂O vapours                   (d) H₂O liquid, H₂O vapours

Answer Key:

(1)-(c); (2)-(a); (3)-(d); (4)-(b); (5)-(a); (6)-(c); (7)-(b); (8)-(d); (9)-(b); (10)-(d); (11)-(b); (12)-(a); (13)-(b); (14)-(a); (15)-(d); (16)-(b)