Question
Tue April 19, 2011 By:
 

In 5th or 6th standard, We studied a chemical reaction that liberates Carbon dioxide,and test its presence by passing it through lime water.........Can you help to recall that chemical reaction...?

Expert Reply
Tue April 19, 2011
When Carbon dioxide is passed through lime water it turns milky
Calcium hydroxide of lime water reacts with carbon dioxide to form an insoluble precipitate of calcium carbonate .
Ca(OH)2 + CO2 ? CaCO3 + H2O
When excess carbon dioxide is passed the milkiness disappears due to formation of soluble calcium bicarbonate.
 

 CaCO3+H2O+CO2->Ca(HCO3)2

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