Give a chemical test to distinguish between the following gases:

Sulphur dioxide and chlorine

On heating which of the following substances i.e., copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate - relate to the reactions given below.

(a) A white substance which leaves an amphoteric oxide as a residue [whose colour varies in the heated and in the cold state] and evolves a gas which turns lime water milky.

(b) An efflorescent substance which leaves a residue having the same colour as the substance and evolves a gas which changes the colour of cobalt chloride paper.

(c) A white solid which evolves two colourless gases which on cooling combine and condense on the cooler parts of the test tube.

(d) A coloured substance which decomposes violently leaving a coloured residue and evolving two neutral gases one of which is unreactive or inert in nature.

(e) A coloured substance which leaves a black residue and evolves two gases one of which is acidic and the other neutral and colourless.

(f) A coloured substance which leaves on strong heating a black residue and evolves two colourless gases one of which is acidic and other neutral.

(g) A white crystalline solid which decrepitates on heating leaving a residue which fuses with the glass and evolves two gases one of which is coloured and acidic.

(h) An amorphous substance which turns from pale green to black on strong heating evolving a colourless, acidic gas as the only gaseous product.

Using dilute sulphuric acid how would you differentiate between :

(a) Copper and magnesium

(b) Sodium carbonate, sodium sulphide and sodium sulphite

How would you identify the gaseous product evolved.

Using a platinum wire, conc. hydrochloric acid and a bunsen burner how would you distinguish between the three salts i.e., sodium chloride, potassium chloride and calcium chloride. Explain in brief the method used for the same.