A' is a blue coloured crystaline salt . On heating it loses blue colour and to give 'B' when water is added ,'B' gives back to 'A' Identify A and B, write the equation .

Identify the compound (A) which is a universal solvent. Compound A reacts with chlorine gas to give B and C. Compound A dissolves in an ionic compound of silicon to give compound D. Identify A and write the equations involved in the formation of B, C and D.

When blue coloured copper sulphate crystals are heated , it becomes _______ copper sulphate .

The chief ore of Zinc, on roasting gave a compound A, which on reduction by carbon, gives B. Identify A and B, give the chemical reactions.

(b) Compound A is used in the manufacture of optical. A on heating gives B. B further heating to form C. A reacts with hydrochloric acid to give D. Identify A, B,C and D. Explain the reaction.