What do you observe when :

(i) Ammonium chloride crystals are heated in a test tube ?

(ii) Iron nails are added to copper sulphate solution ?

(iii) Lead nitrate crystals are heated strongly?

(iv) Silver nitrate solution is mixed with sodium chloride solution?

(v) Blue copper sulphate crystals are heated ?

(i) On heating ammonium chloride, white crystalline solid sublimates to form a basic gas (NH₃) and acidic gas (HCl). The dense white fumes are noticed that form a white mass on the cooler parts of the test tube. No residue is left behind.

(ii) When iron nail is kept in a blue coloured copper sulphate solution for sometime, a reddish brown coating is seen on the iron nail and the colour of the solution changes gradually from blue to light green. The reason for this observation is that iron being more reactive than copper, displaces copper from the solution and copper is deposited on the iron nail

(iii) When solid lead nitrate is heated strongly, it decomposes to produce light yellow solid lead monoxide, reddish brown nitrogen dioxide gas and colourless oxygen gas.

(iv) When silver nitrate solution is mixed with sodium chloride solution, a white ppt of silver chloride is formed along with sodium nitrate.

(v) The blue coloured hydrous copper sulphate changes to white anhydrous copper sulphate releasing water of crystallization.