How gold ornaments are cleaned by aqua re-gia? Write the reactions involved in it.

How sodium carbonate is prepared in the laboratory? Write the reaction involved in the process.

How ethanol is prepared from molasses? Write the various reactions involved?

In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.

A blackish brown coloured solid 'A' when fused with alkali metal hydroxides in presence of air, produces a dark green coloured compound 'B' which on electrolytic oxidation in alkaline medium gives a dark purple coloured compound 'C' Identify A, B and C and write the reactions involved.

How K_2Cr_2O_7 is prepared? Write the necessary reactions involved.

A Ketone 'A' Which undergoes haloform reac-tion gives compound B on reduction. B oheatign with H_2SO_4 gives compound C, which forms mono-ozonide D. D on hydroly-sis in presence of Zn dust gives only acetaldehyde. Identify A, B and C. Write down the reactions involved.

A sweet smelling organic compound 'A' is slowly oxidised by air in presence of light to a higly posionous gas. On warming compound A with silver powder, it forms a gaseous substance 'B' which is also produced by the action of calcium carbide on water. identify 'A' and 'B' and write the chemical reactions involved.

An organic compound contains A(C_7H_5N) on hydrolysis with strong aqueous acid gives another compound B which is a monobasic aromatic carboxylic acid. The compound B on treatment with ammonia gives a salt which on heating gives C. The compound C undergoes Hofmann's bromamide reaction to yield aniline. Name A, B and C and write the chemical reactions involved.

What are polyamides? How Nylon-6,6 is pre-pared? Write the reaction.

How is nylon-6, 6 synthesised? Write the chemical equation for the reaction involved.