InterviewSolution
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InterviewSolution
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What is the action of nitrous acid on ethyl amine ? |
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Answer» Solution :REACTION of an amine with nitrous acid(HO - N =O)is the distinguishing test between primary, secondary and tertiary amines as they react differently with nitrous acid. Nitrous acid is unstable, hence prepared instantly by the action of cold, dilute, hydrochloric acid on sodium nitrite. `underset("Sodium nitrite")(NaNO_(2)) + HCI overset("cold")underset("dil.")to NaCI + underset(" nitrous acid")(HNO_(2))` (1) Action of nitrous acid on primary amine : All primary amines, except methly amine react withnitrous acid in cold to give alcohol and liberate nitrogen gas. For example, ethyl amine on reaction with nitrous acid in cold, forms ethyl alcohol and nitrogent gas. `underset("ethylamine")(C_2H_5 -NH_2)+underset("nitrous acid")(HO-N=O) overset(NaNO_(2)+ " dill. HCI")underset("cold")to underset("ethyl alcohol")(C_(2)H_(5)-OH)H_(2)O+underset("nitrogen gas")(N_(2))` (2) Action of nitrousacid on secondary amines : Tertiary amine on reaction with nitrous acid forms N-nitrosoamine which is a pale yellow oil. Forexample, diethyl amine on reaction with nitrous acid in cold froms pale yellow oily N-nitrosodiethylamine. `underset("diethylamine")((C_(2)H_(5))_(2)NH)+H-O-H=O overset(NaNO_(2)+ " dil.HCI") underset("cold")to underset("N-nitrosodiethylamine")((C_(2)H_(5))_(2)N-N=O + H_(2))O` (3) Action of nitrous acid on tertiary amines , Tertiary amine on reaction with nitrous acid forms water - soluble nitrite salt. As no visible change , is OBSERVED , it is said that there is no reaction. For example, TRIETHYLAMINE reacts with nitrous acid in cold and forms water soluble triethyl ammonium nitrite salt. `underset("triethyaminenitrous acid")((C_(2)H_(5))_(3)N+HO-N=O) overset(NaNO_(2)+ " dil. HCI")underset("cold")to underset("triethyl ammonium nitrite")([(c_(2)H_(5))_(3)NH^(+)]NO_(2)^(-))` |
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