Wxplain why :
(i) Common salt becomes stick during the rainy season
(ii) Blue vitriol changes ot wihte upon heating
(iii) If bottle full of concentrated sulphuric acid is left open in the atmosphere by accident. The acid starts flowing out of the bottle of its own.

A mixture of two salt was treated as follows : i. The mixture was heated with magnanese dioxide and concentrated sulphuric acid , when a yellowish -green gas was liberated. ii. The mixture on heating with sodium hydroxide solution gave a gas which turned red litmus blue iii. Its solution in water gave a blue precipitate with potassium ferricyanide and red colourtion with ammonium thiocynate iv. The mixture was boiled with potassium hydroxide and the librated gas was bubbled through an alkline solution of K_(2)HgI_(4) to give a brown precipitate identify the two salts gives ionic equation for the reaction involved in the tests (i) , (ii) and (iii).

From the formulae listed in the box, choose one in each case corresponding to the salt having the given description: AgCl,CuCO_(3),CuSO_(4)*5H_(2)O,KNO_(3),NaCl,NaHSO_(4),Pb(NO_(3))_(2) , (i) an acid salt (ii) an insoluble chloride (iii) on treating with concentrated sulphuric acid, this salt changes from blue to white. (iv) on heating, this salt changes from green to black. (v) this salt gives nitrogen dioxide on heating.