Question

When calcium is added to water, it starts floating. What products are formed in this reaction?​

Answer 1

Explanation:

Calcium is an alkaline earth metal, and little less reactive as compared to Alkali metals (Na, K) etc. But still, they are very reactive and can react with Cold Water vigorously.

The Reaction is:

$\rm{Ca + 2H_2O \longrightarrow \: Ca(OH)_2 + H_2}$

The reaction is little less violent as compared to reaction of water with alkali metals. But, Calcium reacts with Cold water to form Calcium hydroxide and Hydrogen gas. The presence of H2 can be tested with popping sound.

Coming back to question:

The hygrogen gas evolved in this reaction stick to the surface of metals like Calcium and magnesium. The hydrogen gas stick in the form of H2 bubbles, this makes it lighter to float on the surface✓.

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Answer 2

Explanation:

CONCEPT:

CALCIUM (Ca) IS AN ALKALINE EARTH METAL AND LESS REACTIVE THAN ALKALI METALS LIKE SODIUM (Na) AND POTASSIUM (K),BUT IT WILL REACT VIGOROUSLY WHEN ADDED IN WATER (H20).

QUESTION:

WHAT PRODUCTS ARE FORM IN THIS REACTION WHEN CALCIUM IS ADDED TO WATER?

ANSWER:

WHEN CALCIUM REACT WITH WATER IT FORM CALCIUM HYDROXIDE AND HYDROGEN GAS.

AND CALCIUM IS FLOATING AS BECAUSE HYDROGEN MOLECULES STICK TO IT AS HYDROGEN MOLECULES ARE VERY LIGHT.