Multiple choice general knowledge science & technology

The element which gets ignited off while contact with water

  1. Grano magnesium

  2. Metallic potassium

  3. Ethiline

  4. Ethanol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metallic potassium (option B) is highly reactive with water and ignites spontaneously upon contact, producing hydrogen gas and heat. The reaction is 2K + 2H2O → 2KOH + H2 + heat. Granulated magnesium (A) doesn't ignite in water at room temperature, 'Ethiline' (C) appears to be a typo for ethylene or a similar compound, and ethanol (D) is miscible with water without ignition.

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