Question

(i). Write the reaction involved when

(a). Carbon dioxide gas is passed through lime water.          

 (b). Excess of carbon dioxide is passed through the solution obtained from .      

 (ii). Name the acids present in lemon and ant sting.​

Answer 1

Explanation:

So when Carbon dioxide ( ) is passed through lime water, an Acid-Base reaction takes place producing salt and water. The reaction is written as, Calcium Carbonate ( ) is insoluble in water, thus forming white precipitate, making the solution appear milky. This also serves as the classic test for carbon dioxide.

Answer 2

Answer:

The gas evolved because of reaction of acid with metal carbonate or metal hydrogen carbonate turns lime water milky. This shows that the gas is carbon dioxide gas. This happens because of formation of white precipitate of calcium carbonate.

Ca(OH)2 + CO2 ⇨ CaCO3 + H2O

CaCO3 + CO2 + H2O ⇨ Ca(HCO3 )2

But when excess of carbon dioxide is passed through lime water, it makes milky colour of lime water disappear. This happens because of formation of calcium hydrogen carbonate. As calcium hydrogen carbonate is soluble in water, thus the milky colour of solution mixture disappears.