(i) Solid calcium oxide was taken in a container and water was added slowly to it : (a) Write the observation . (b) Write the chemical formula of the product formed (ii) What happens when carbon dioxide gas is bubbled through lime water : (a) In small amount , (b) In excess? (iii) Why do you apply paint on iron articles ?

(i) Solid calcium oxide was taken in a container and water was added s

1.	(i) Solid calcium oxide was taken in a container and water was added slowly to it : (a) Write the observation . (b) Write the chemical formula of the product formed (ii) What happens when carbon dioxide gas is bubbled through lime water : (a) In small amount , (b) In excess? (iii) Why do you apply paint on iron articles ?
Answer» Solution :(i) (a) Calcium OXIDE a LARGE reacts vigorously with water and releases a large amount of heat . (b) Calcium hydrooxide (Slaked lime ) i.e., `Ca(OH)_(2)` is formed . (iii) (a) In small amount, solution becomes milky due to the formation of calcium carbonate . `Ca(OH)_(2)+CO_(2)rarrCACO_(3)+H_(2)O`. (b) In excess,milkiness disappears because calcium carbonate changes to calcium hydrogencarbonate which is colourless in nature. `CaCO_(3)+H_(2)O+CO_(2)rarrunderset("Colourless") (Ca(HCO_(3))_(2))` (iii) Paint forms a projective COATING on the surface of iron , so thatoxygen and moisture present in theair cannot have a direct contact with iron .