Which observation is made when potassium reacts with water?
Answer and explanation
Correct answer: C. It moves on the surface, melts, and burns with a lilac flame
- Step 1: is very exothermic.
- Step 2: The heat melts the potassium and ignites the hydrogen, which burns with a lilac flame.
Answer
It moves on the surface, melts, and burns with a lilac flame.
Why not the others: It sinks and reacts slowly without a flame: potassium is less dense than water and reacts vigorously. It stays still and forms a coloured precipitate: potassium floats and moves as hydrogen is released. It fizzes gently without melting: the reaction is violent enough to melt the metal.
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More Group chemistry questions
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