Amines quiz

Which of the following is a secondary amine?

Hoffmann bromamide degradation of propanamide gives:

The carbylamine test is given by:

Which is the weakest base?

Aniline does not undergo Friedel-Crafts reaction because:

Benzenediazonium chloride on treatment with CuCN gives:

Aniline reacts with bromine water at room temperature to give:

The product of reaction of benzenediazonium chloride with H3PO2 is:

Sulphanilic acid exists as a:

Which amine does NOT react with Hinsberg's reagent?

Why do primary amines have higher boiling points than tertiary amines of comparable molecular mass? (2 marks)

Write the equation for the ammonolysis of an alkyl halide. Why is it not a good method for preparing pure primary amines? (2 marks)

Why is aniline acetylated before nitration? (2 marks)

What happens when ethanamine reacts with nitrous acid? Write the equation. (2 marks)

Distinguish between the Sandmeyer reaction and the Gatterman reaction. (2 marks)

Why is benzenediazonium chloride not stored but used immediately? (2 marks)

Give a chemical test to distinguish between aniline and N-methylaniline. (2 marks)

Write the equation for the coupling of benzenediazonium chloride with phenol. (2 marks)

Why are amines less acidic than alcohols of comparable molecular mass? (2 marks)

Write the equation for the reduction of ethanenitrile with LiAlH4. (2 marks)

The pKb of aniline is 9.38. Calculate Kb (antilog of -9.38 = 4.17 x 10^-10). Calculate [OH-] in a 0.1 M solution (sqrt(4.17 x 10^-11) = 6.46 x 10^-6). (3 marks)

Calculate the volume of nitrogen at STP evolved when 4.5 g of ethanamine reacts completely with nitrous acid (C2H5NH2 = 45, molar volume 22.4 L). (3 marks)

Calculate the mass of benzenediazonium chloride (C6H5N2Cl = 140.5) formed from 9.3 g of aniline, and the mass of phenol (94) obtained from it on hydrolysis, assuming 100% yield at each step. (3 marks)

An amine contains 23.73% nitrogen. If its molar mass is 59 g/mol, how many nitrogen atoms does it contain? Suggest a possible structure. (3 marks)

Calculate the mass of 2,4,6-tribromoaniline (330) formed when 1.86 g of aniline (93) reacts with excess bromine water, and the mass of bromine (Br2 = 160) consumed. (3 marks)

Read the passage and answer the questions. A student was given three unlabelled amines: ethanamine, N-ethylethanamine and N,N-diethylethanamine. She treated each with benzenesulphonyl chloride and then with aqueous KOH. (i) Which amine gave a product soluble in KOH? Explain. (ii) Which gave an insoluble product? (iii) Which did not react? Why? (5 marks)

Read the passage and answer the questions. In a dye factory, aniline is dissolved in dilute HCl and cooled in ice. Sodium nitrite solution is added slowly, and the resulting solution is added to alkaline phenol to give an orange dye. (i) Name the reaction that forms the first product and write the equation. (ii) Name the orange dye and the reaction forming it. (iii) Why is the temperature kept low? (5 marks)

Read the passage and answer the questions. A chemist wants pure ethanamine. Ammonolysis of ethyl bromide gives a mixture. Instead, she treats phthalimide with ethanolic KOH, then with ethyl bromide, and finally hydrolyses the product. (i) Name the method. (ii) Write the steps. (iii) Why can it not prepare aniline? (5 marks)

Read the passage and answer the questions. Aniline is a colourless liquid when freshly prepared but darkens on storage. It is a weaker base than ammonia and forms anilinium chloride with HCl. (i) Why does aniline darken on storage? (ii) Why is aniline a weaker base than ammonia? (iii) Write the equation for its reaction with HCl. (5 marks)

Read the passage and answer the questions. A compound X (C2H7N) reacts with nitrous acid to give an alcohol and nitrogen gas, and with chloroform and alcoholic KOH gives a foul-smelling compound. (i) Identify X. (ii) Name the reaction with chloroform and write the equation. (iii) Name the alcohol formed with nitrous acid. (5 marks)

Describe five methods of preparation of amines with equations, including Gabriel synthesis and Hoffmann bromamide degradation. (6 marks)

Explain the basic character of amines. Draw the structures to explain the effect of resonance on the basicity of aniline, and compare aliphatic and aromatic amines. (6 marks)

Describe the electrophilic substitution reactions of aniline: bromination, nitration and sulphonation, with structures, and explain the role of the -NH2 group. (6 marks)

Describe the preparation of benzenediazonium chloride and its reactions involving displacement of nitrogen, with a flowchart. (6 marks)

Explain the methods to distinguish primary, secondary and tertiary amines: Hinsberg's test, nitrous acid test and carbylamine test, with equations and a chart. (6 marks)