Multiple choice

Why is water not suitable for fire involving oil and petrol?

  1. Because water is lighter than oil and it flows over oil.

  2. Water is heavier than oil and sinks below it.

  3. It mixes with oil and both start burning.

  4. Water increases the ignition temperature of oil.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water is not suitable for oil and petrol fires because water is heavier than oil and petrol. When water is poured on burning oil, it sinks below the oil surface due to higher density. The oil, being lighter, continues to float on top and keeps burning. Moreover, the water can boil and create steam explosions, spreading the burning oil further. This is why foam or CO2 extinguishers are used instead.

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