Inorganic reactions
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What do you see when calcium reacts with water? Also how do would you SEE hydrogen gas being given off? and what is calcium hydroxide solution used to test for?
The two products are calcium hydroxide and hydrogen. The pieces of calcium may sink at first, then rise as bubbles of a colourless gas form on the surface of the metal. The effervescence will be quite vigorous.
Calcium hydroxide is only very sparingly soluble in water, so quite soon a precipitate of the white hydroxide forms turning the mixture cloudy white.
A saturated solution of calcium hydroxide, which could be obtained by filtering the above mixture when the reaction is over, is called limewater. It used to test for carbon dioxide. Bubbling the gas through it turns it milky as a white precipitate of calcium carbonate forms.
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updated: 17 December 2006
