Answer
Verified
461.4k+ views
Hint: We know that azo dye test is used for identification of aromatic primary amines. Primary amine is the amine which is in the form of ${\rm{R}} - {\rm{N}}{{\rm{H}}_{\rm{2}}}$ (R is any alkyl group).
Complete step by step answer:
The aromatic primary amine can be confirmed by azo dye test. In this test, primary aromatic amine like aniline reacts with nitrous acid (produced by reaction of sodium nitrite with hydrochloric acid) at zero to five degree Celsius to form diazonium salt or benzene diazonium chloride. The reaction of formed benzene diazonium chloride with $\beta $-naphthol gives a scarlet red dye and this die is sparingly soluble in water. The reaction can be shown as follows:
Let’s come to the question. We have to identify the type of solution of $\beta $-naphthol to be used in dye test. If the solution of $\beta $-naphthol is alkaline, -OH convert to ${{\rm{O}}^ - }$ which reacts with azo compound (benzene diazonium chloride) to form azo dye. The chemical reaction is shown below.
Hence, the correct option is D, that is, an alkaline solution.
Additional Information Another test of amine is carbylamine test. In this test aromatic as well as aliphatic primary amine is heated with chloroform to result in carbylamine. The reaction is,
${\rm{R}} - {\rm{N}}{{\rm{H}}_{\rm{2}}} + {\rm{CHC}}{{\rm{l}}_{\rm{3}}} + 3{\rm{KOH}} \to {\rm{RNC}}\left( {{\rm{Carbylamine}}} \right) + 3{\rm{KCl + 3}}{{\rm{H}}_2}{\rm{O}}$
Note: It is to be noted that aromatic primary can be distinguished from secondary and tertiary amine by azo dye test and aliphatic or aromatic primary amine can be differentiated from secondary and tertiary amine by Carbylamine test.
Complete step by step answer:
The aromatic primary amine can be confirmed by azo dye test. In this test, primary aromatic amine like aniline reacts with nitrous acid (produced by reaction of sodium nitrite with hydrochloric acid) at zero to five degree Celsius to form diazonium salt or benzene diazonium chloride. The reaction of formed benzene diazonium chloride with $\beta $-naphthol gives a scarlet red dye and this die is sparingly soluble in water. The reaction can be shown as follows:
Let’s come to the question. We have to identify the type of solution of $\beta $-naphthol to be used in dye test. If the solution of $\beta $-naphthol is alkaline, -OH convert to ${{\rm{O}}^ - }$ which reacts with azo compound (benzene diazonium chloride) to form azo dye. The chemical reaction is shown below.
Hence, the correct option is D, that is, an alkaline solution.
Additional Information Another test of amine is carbylamine test. In this test aromatic as well as aliphatic primary amine is heated with chloroform to result in carbylamine. The reaction is,
${\rm{R}} - {\rm{N}}{{\rm{H}}_{\rm{2}}} + {\rm{CHC}}{{\rm{l}}_{\rm{3}}} + 3{\rm{KOH}} \to {\rm{RNC}}\left( {{\rm{Carbylamine}}} \right) + 3{\rm{KCl + 3}}{{\rm{H}}_2}{\rm{O}}$
Note: It is to be noted that aromatic primary can be distinguished from secondary and tertiary amine by azo dye test and aliphatic or aromatic primary amine can be differentiated from secondary and tertiary amine by Carbylamine test.
Recently Updated Pages
Who among the following was the religious guru of class 7 social science CBSE
what is the correct chronological order of the following class 10 social science CBSE
Which of the following was not the actual cause for class 10 social science CBSE
Which of the following statements is not correct A class 10 social science CBSE
Which of the following leaders was not present in the class 10 social science CBSE
Garampani Sanctuary is located at A Diphu Assam B Gangtok class 10 social science CBSE
Trending doubts
A rainbow has circular shape because A The earth is class 11 physics CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Which are the Top 10 Largest Countries of the World?
How do you graph the function fx 4x class 9 maths CBSE
The Constitution of India was adopted on A 26 November class 10 social science CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
Change the following sentences into negative and interrogative class 10 english CBSE