A green oxide of chromium(A), on fusion with KOH and `KNO_3` gives a yellow compound (B). The aqueous solution of (B) on acidification with dilute `H_2SO_4` gives an orange coloured compoud (C). Identify (B) and (C) and write down balanced chemical equations involved.

An organic compound (A) with molecular formula C_(6)H_(7)N gives (B) with HNO_(2)//HCl at 273 K. The aqueous solution of (B) on heating gives compound (C) which gives violet colour with neutral FeCl3. Identify the compounds A, B and C and write the equations.

A liquid A is treated with Na_(2)CO_(3) solution. A mixture of two salts B and C are produced in the solution. The mixture on acidification with H_(2)SO_(4) and distillation produces the liquid A again. Identify A, B and C and write the equations involved.

When chromite ore FeCr_(2)O_(4) is fused with NaOH in presence of air, a yellow coloured compound (A) is obtained which on acidification with dilute sulphuric acid gives compound (B). Compound (B) on reaction with KCl forms an orange colured crystalline compound (C ). Write one use of compound (C ).

When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic solution to give purple compound (C ). An alkaline solution of compound (C ) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds (A) to (D) and also explain the reactions involved.

A ketone A, which undergoes halform reaction, gives compound B on reduction B on heating with sulphuric acid gives compounds C, which forms mono-ozonide D.D on hydrolysis in the presence of zinc dust gives only acetaldehyde. Identify A, B and C. Write down the reaction involved.

A compound (A) (C_7H_4N) on hydrolysis with strong aqueous acid gives another 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. Identify A, B, C and write chemcial reactions involved.

The molecular formula of an organic compound is C_2H_4O_2 . The compound is soluble in water and on addition of NaHCO_3 to the aqueous solution of the compound CO_2 is evolved. Identify the organic compound. Write, with conditons and balanced chemical equation, the reaction of the compound with ethanol.

BF_(3) reacts with LiH and forms a compound A. The compound A reacts with water to give the compound B. A reacts with ammonia at 390 K and form C. Identify (A), (B) and (C).

The aqueous solution of a salt (A) is alkaline. When (A) is heated strongly, it swells up and melts to give a transparent bead. When the bead is heated with a sulphate salt (C), the bead becomes deep blue in colour. A white crystalline compound (D) is obtained when concentrated H_2SO_4 is added to a hot solution of (A). Identify (A), (B), (C) and (D) and give the reactions involved.