Fuels, Combustion and Flame Worksheet-3

Fuels, Combustion and Flame Worksheet-3

1. The fires can be of different origin, and hence different substances are used to extinguish them. Water cannot be used as fire extinguisher to put out:

(a) burning wood                         (b) burning oil

(c) burning cloth                          (d) burning charcoal

2. Which type of fire extinguisher is used to extinguish fire caused by burning oil and petrol?

(a) Foam type                                (b) Water type

(c) Soda acid type                         (d) CCl₄ type

3. The type of combustion in which heat, light and sound are produced is:

(a) Rapid                                        (b) Explosive

(c) Spontaneous                            (d) none of these

4. Which of the following is an ideal fuel?

(a) Coal              (b) LPG              (c) Petrol           (d) None of these

5. The incomplete combustion of a fuel gives:

(a) CO                (b) C0₂               (c) S0₂                (d) oxides of nitrogen

6. Combustion ,which is the heating of substances in excess supply of oxygen is an:

(a) exothermic reaction              (b) endothermic reaction

(c) displacement reaction          (d) reduction reaction

7. The disadvantages of incomplete combustion is/are:

(a) unburnt carbon gets released

(b) air is polluted

(c) may cause respiratory problems

(d) all of the above

8. A chemical factory in Gujarat caught fire in 2010. Which of the following Gases were present there which was combustible, and supported combustion, which eventually destroyed the factory?

(a) Oxygen                                     (b) Nitrous Oxide

(c) Nitric Oxide                             (d) Carbon dioxide

9. Type of flame produced by a fuel depends upon:

(a) (a) calorific value

(b) (b) amount of oxygen

(c) (c) type of fuel and its chemical composition

(d) (d) all of these

10. Which of the following statements is NOT true?

(a) CO₂ is the best fire extinguisher

(b) Global warming can cause acid rain

(c) Burning of coal and diesel releases sulphur dioxide gas

(d) LPG has higher calorific value than biogas

Answer Key:

(1)-(b); (2)-(a); (3)-(b); (4)-(d); (5)-(a); (6)-(a); (7)-(d); (8)-(b); (9)-(b); (10)-(b)