Reaction With Nitrous Acid

Which of the following on reactions with nitrous acid, followed by treatment with NaOH produces a blue coluration?

Which of the following on reactions with nitrous acid, followed by treatment with NaOH produces a blue coluration?

Explain how does the presence or absence of hydrogen on nitrogen of amines affect the modes of their reactions with nitrous acid.

Copper metal on treatemet with dilute HNO_(3) produces a gas X,X when passed through acidic solution of stannous chloride, a nitrogen containing compound Y is obtained. Y on reaction with nitrous acid produces a gas Z. Then

An organic compound A with molecular formula C_2 H_7 N on reaction with nitrous acid gives a compound B.B on controlled oxidation gives a compound C. C reduces Tollens' reagent to give silver mirror and D. B reacts with D in the presence of concentrated sulfuric acid to give a sweet smelling compound E. Identify A, B, C, D and E. Give the reaction of C with ammonia and name the product.

Reaction of nitrous acid wiith aliphatic primary aminie in cold gives