Fuels, Combustion and Flame Worksheet-6

Fuels, Combustion and Flame Worksheet-6

1. Which of the following is an example of rapid combustion?

(a) Candle                                      (b) Cracker

(c) White phosphorus                 (d) None

2. Fire is extinguished by:

(a) removing all combustible substance

(b) cutting off supply of air

(c) cooling the burning substance

(d) all of these

3. Water cannot be used as fire extinguisher to put out:

(a) burning wood                         (b) burning oil

(c) burning cloth                          (d) burning charcoal

4. In soda-acid fire extinguisher

2NaHCO₃ + H₂SO₄ → ?

(a) Na₂SO₄ + 2H₂O + 2CO₂       (b) Na₂SO₄ + CO₂ + O₂

(c) Na₂SO₄ + H₂O + O₂               (d) Na₂SO₄ + H₂O₂

5. In soda-acid fire extinguisher ____ helps in putting out the fire.

(a) CO₂                                            (b) CO₂ + H₂O

(c) H₂O                                           (d) CO

6. In foam type fire extinguishers, which of the following products are formed?

Al₂ (SO₄)₃ + 6NaHCO₃ → ?

(a) 2Al (OH)₃ + 6H₂O + 3NaSO₄

(b) 2Al (OH)₃ + 6CO + 3NaSO₄

(c) 2Al (OH)₃ + 6O₂ + 3NaSO₄

(d) 2Al (OH)₃ + 6CO₂ + 3Na₂SO₄

7. In foam type fire extinguisher _____ is responsible to put off fire.

(a) H₂O              (b) CO₂ + H₂O  (c) CO₂               (d) CO

8. 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

9. In foam type extinguisher ____ is present in bottle.

(a) NaHCO₃      (b) Al (SO₄)₃     (c) Al (OH)₃      (d) Na₂SO₄

10. In foam type extinguisher _____ is present in the cylinder.

(a) Al₂ (SO₄)₃    (b) NaHCO₃      (c) Na₂SO₄        (d) Al (OH)₃

Answer Key:

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