Practice Questions

Apply the carbylamine test to distinguish between ethylamine and N-ethylethanamine.

Name the type of intermolecular bonding responsible for the solubility of lower aliphatic amines in water.

Identify the accepted IUPAC name for aniline ($C_6H_5NH_2$).

Name the geometry of amines and the hybridization of the nitrogen atom.

Demonstrate how to convert butanamide into propanamine. Name the reaction and write the chemical equation.

Propose a reason based on electronic effects for why aryldiazonium salts are significantly more stable than alkyldiazonium salts.

Examine why ethylamine ($C_2H_5NH_2$) is soluble in water, but N,N-diethylaniline ($C_6H_5N(C_2H_5)_2$) is insoluble.

Define a primary amine with a general chemical formula.

Explain the term 'diazotisation' and provide the chemical equation for the preparation of benzenediazonium chloride.

Name the major organic product formed when aniline reacts with excess aqueous bromine ($Br_2(aq)$) at room temperature.

Design a two-step synthesis to convert toluene ($C_6H_5CH_3$) into benzylamine ($C_6H_5CH_2NH_2$). Then, propose a method to convert this benzylamine into N-benzylacetamide.

An amine with the molecular formula $C_4H_{11}N$ is treated with benzenesulphonyl chloride ($C_6H_5SO_2Cl$). The resulting product is insoluble in aqueous $KOH$. Solve for the structure and IUPAC name of the amine.

Solve for the final product when p-toluidine (4-methylaniline) is treated with $NaNO_2$ and $HCl$ at $273-278$ K, followed by reaction with an aqueous solution of phenol. Write the structure and name of the final product.

Contrast the boiling points of butan-1-ol and butan-1-amine. Analyze the underlying reason for the difference.

Analyze why Gabriel phthalimide synthesis is not suitable for preparing aniline.

Demonstrate the synthesis of butan-1-amine from propan-1-ol. This synthesis involves an ascent of series (increasing the carbon chain length).

A student attempts to prepare ethylamine ($CH_3CH_2NH_2$) via ammonolysis of ethyl chloride ($CH_3CH_2Cl$) and obtains a mixture of primary, secondary, and tertiary amines, as well as a quaternary ammonium salt. Critique this method and propose a modification to maximize the yield of the primary amine.

Design a single chemical test to distinguish between ethylamine ($C_2H_5NH_2$) and aniline ($C_6H_5NH_2$). Justify your choice and describe the expected observations.

Describe the carbylamine reaction and state its primary use.

List the products formed when an amide is treated with bromine in an aqueous solution of sodium hydroxide, and name this reaction.

Recall the order of reactivity of alkyl halides with amines in the ammonolysis reaction.

Describe two reactions of diazonium salts involving the displacement of nitrogen. Name these reactions and provide one chemical equation for each.

Compare the basic strength of ethanamine, N,N-diethylethanamine, and aniline in aqueous solution. Analyze the factors responsible for the observed order.

Propose a critical reason why direct nitration of aniline with a mixture of concentrated $HNO_3$ and $H_2SO_4$ is not a suitable method for preparing p-nitroaniline.

Demonstrate the conversion of nitrobenzene into benzoic acid. Outline all the intermediate steps and reagents required.

Examine why direct nitration of aniline with a mixture of concentrated $HNO_3$ and $H_2SO_4$ yields a significant amount of m-nitroaniline (47%), even though the amino group is an ortho-para director.

Contrast the reaction of primary aliphatic amines (e.g., ethanamine) and primary aromatic amines (e.g., aniline) with nitrous acid ($HNO_2$). Analyze why the products differ in stability.

Evaluate the statement: 'Gabriel phthalimide synthesis is the most versatile method for preparing all types of primary amines.' Justify your conclusion.

Justify why aniline ($C_6H_5NH_2$) is a much weaker base than cyclohexylamine ($C_6H_{11}NH_2$), using resonance structures to support your argument.

Evaluate the relative boiling points of the isomeric amines: butan-1-amine ($C_4H_9NH_2$), N-ethyl-ethanamine ($(C_2H_5)_2NH$), and N,N-dimethyl-ethanamine ($C_2H_5N(CH_3)_2$). Justify the trend based on intermolecular forces.

Explain why the boiling points of primary amines are higher than those of isomeric tertiary amines.

Critique the use of the Friedel-Crafts reaction (alkylation or acylation) on aniline.

Explain why aniline is a weaker base than ammonia.

Explain why the direct nitration of aniline yields a significant amount of m-nitroaniline, even though the amino group is ortho-para directing.

Justify the observed order of basicity in the gaseous phase for methylamines: $(CH_3)_3N > (CH_3)_2NH > CH_3NH_2 > NH_3$. Contrast this with the typical order in aqueous solution and evaluate the factors responsible for the difference.

Formulate the reaction mechanism for the coupling reaction between benzenediazonium chloride and phenol. Identify the electrophile and nucleophile and justify why the coupling occurs predominantly at the para position.

Ammonolysis of bromoethane is carried out using an excess of bromoethane instead of ammonia. Analyze the products formed and explain why this method is not suitable for preparing primary amines as the major product.

A mixture contains aniline, N-methylaniline, and N,N-dimethylaniline. Demonstrate a chemical procedure using benzenesulphonyl chloride to distinguish and separate these three amines. Write the reactions involved.

Create a reaction scheme to convert propanoic acid ($CH_3CH_2COOH$) into ethanamine ($CH_3CH_2NH_2$). Name each reaction and justify the choice of reagents for each step.

A student has a mixture of a primary amine ($RNH_2$), a secondary amine ($R_2NH$), and a tertiary amine ($R_3N$). Design a chemical procedure based on the Hinsberg test to separate these three compounds from the mixture.

Compare the basicity of methylamine, dimethylamine, and trimethylamine in the gaseous phase. Contrast this order with their basicity order in an aqueous solution and analyze the reasons for the difference.

Summarize the Gabriel phthalimide synthesis and explain why it cannot be used to prepare aromatic primary amines.

Describe how primary, secondary, and tertiary amines are distinguished using Hinsberg's reagent (benzenesulphonyl chloride).

Formulate a complete synthetic route to prepare 1,3,5-tribromobenzene starting from aniline. You must use a diazonium salt intermediate. Write all the chemical equations involved.

Design a multi-step synthesis pathway to convert benzene into p-bromoaniline. Justify the choice of reagents and the sequence of reactions, especially the use of a protecting group.