Tests for Amines - MeitY OLabs

Summary

The video 'Tests for Amines' from MeitY OLabs explains the chemical nature and identification tests for amines, which are derivatives of ammonia where hydrogen atoms are replaced by alkyl or aryl groups, forming primary, secondary, or tertiary amines. Known amine-containing compounds include nicotine and caffeine. The video describes several tests for identifying amines, including solubility, litmus, azo-dye, nitrous acid, and Hinsberg tests. Each test involves a distinct set of materials and steps, aiming to observe specific reactions like color change or gas formation. The video emphasizes safety precautions in handling hazardous chemicals like hydrochloric acid and ensures a comprehensive understanding of amine testing through these structured experiments.

Highlights

• Primary, secondary, and tertiary amines can be identified by replacing hydrogen with alkyl/aryl groups. 🎯
• Solubility tests reveal the basicity of amines as they dissolve in mineral acids. 🧪
• Litmus testing indicates amino nature by turning red litmus blue. 🌈
• Azo-dye test produces a scarlet compound with a coupling reaction. 🌺
• Nitrous acid test shows gas or oily layer formation indicating amine type. 🍶
• Hinsberg test differentiates amines based on solubility reactions. 🧊

Key Takeaways

• Amines are ammonia derivatives with hydrogen atoms replaced by alkyl or aryl groups. 🌿
• Simple tests such as solubility, litmus, and azo-dye can identify amines. 🔬
• Nitrous acid and Hinsberg tests distinguish between primary, secondary, and tertiary amines. 📊
• Safety precautions are crucial when handling chemicals like hydrochloric acid. ⚠️

Overview

In the intriguing world of chemistry, amines stand out as derivatives of ammonia, where their defining characteristic lies in the replacement of hydrogen atoms by alkyl or aryl groups. These subtle changes significantly affect the properties of primary, secondary, and tertiary amines, which can be found in everyday compounds like nicotine and caffeine. The video from MeitY OLabs provides keen insights into these variations.

Testing for these amines is made accessible through straightforward experiments like the solubility and litmus tests, which indicate the basicity of the compound by dissolving in mineral acids or changing litmus paper color. More complex reactions, such as the azo-dye test, involve multiple steps to observe coupling reactions resulting in vibrant scarlet hues.

For the curious chemist, distinguishing between the types of amines becomes a detective story with the nitrous acid and Hinsberg tests. These tests not only reveal the identity but also the nature of the amine, showcasing a range of outcomes from the formation of gas bubbles in primary amines to negligible reactions in tertiary. Throughout, the emphasis on safety, especially with hazardous chemicals like hydrochloric acid, ensures that science can be both fun and safe.

Chapters

• 00:00 - 00:30: Introduction to Amines Amines are derivatives of ammonia where hydrogen atoms are replaced by alkyl or aryl groups. A primary amine forms when one hydrogen atom is replaced.
• 00:30 - 01:00: Types of Amines and Objective of the Tests The chapter discusses the types of amines, specifically secondary and tertiary amines, formed by the replacement of hydrogen atoms with alkyl or aryl groups. Examples of amine-containing compounds such as nicotine and caffeine are given. The objective of the chapter is to identify amines using simple tests.
• 01:00 - 01:30: Introduction to Tests for Amines This chapter introduces various tests used for identifying amines. It covers the solubility test, litmus test, azo-dye test, nitrous acid test, and Hinsberg test. The chapter provides a brief overview of the materials required and procedures for the solubility test, including the use of organic compounds, dilute hydrochloric acid, and a dropper.
• 01:30 - 02:30: Solubility Test The chapter titled 'Solubility Test' provides a practical procedure for testing the solubility of organic compounds in mineral acids. It explains that amines, due to their basic nature, can dissolve in mineral acids. The experiment involves shaking a test tube containing an organic compound, performing a litmus test using moist red litmus paper and a dropper, and observing the results. The process asserts the basicity of amines and their reaction tendency with acids.
• 02:30 - 03:30: Litmus Test This chapter titled 'Litmus Test' provides instructions for conducting a chemical test to determine the basicity of a compound. It explains the process of how amines can turn red litmus paper blue, demonstrating their basic nature. Additionally, the chapter briefly mentions materials required for an azo-dye test but does not provide details on the procedure.
• 03:30 - 04:30: Azo-dye Test The Azo-dye Test chapter explains the materials and procedure required for this chemical test. The materials include dilute sodium hydroxide, ice cold water, test tubes, and droppers. The procedure involves taking small quantities of an organic compound, sodium nitrite, and beta-naphthol into separate test tubes labeled A, B, and C. Dilute hydrochloric acid is added to test tube A with a dropper, and the tube is shaken well to dissolve the compound.
• 04:30 - 06:00: Nitrous Acid Test The chapter titled 'Nitrous Acid Test' describes a laboratory experiment involving the preparation and manipulation of solutions. Initially, distilled water is added to test tube B to dissolve sodium nitrite, forming a sodium nitrite solution. Parallelly, a small amount of dilute sodium hydroxide solution is introduced into test tube C to dissolve beta-naphthol. Both test tubes are then cooled in ice cold water to complete the setup necessary for the nitrous acid test. The experiment involves careful handling and mixing of chemicals to obtain desired solutions.
• 06:00 - 08:30: Hinsberg Test The chapter titled 'Hinsberg Test' discusses the chemical reactions involved in identifying primary amines using sodium nitrite solution. The process begins with adding sodium nitrite solution to an organic compound. Primary amines react with nitrous acid, which is produced from sodium nitrite and hydrochloric acid, to form a diazonium salt. This salt is then introduced into test tube C, which contains a beta-naphthol solution. The diazonium salt undergoes a coupling reaction with beta-naphthol, resulting in the formation of a scarlet red compound.
• 08:30 - 09:00: Precautions The chapter discusses 'Precautions' related to handling a compound called azo dye. It involves detailing the use of various materials required for a nitrous acid test, including primary, secondary, and tertiary amines, sodium nitrite, distilled water, concentrated hydrochloric acid, ice-cold water, test tubes, droppers, and spatulas.

Tests for Amines - MeitY OLabs Transcription

• 00:00 - 00:30 Tests for Amines Amines are derivatives of ammonia in which one or more hydrogen atoms are replaced by alkyl or aryl groups. When one of the three hydrogen atoms is replaced by alkyl or aryl group, primary amine is formed.
• 00:30 - 01:00 When two of the three hydrogen atoms are replaced by alkyl or aryl group, secondary anime is formed. When all the three hydrogen atoms are replaced by alkyl or aryl substituents, tertiary amine is formed. Nicotine, present in tobacco leaves, and caffeine, present in seeds of coffee plants, are amine containing compounds. Our aim here is to identify amines using some simple tests.
• 01:00 - 01:30 They are: Solubility test Litmus test Azo - dye test Nitrous acid test Hinsberg Test Solubility test Materials required: Organic compound, dilute hydrochloric acid and dropper. Procedure: Take a small quantity of dilute hydrochloric acid using the dropper.
• 01:30 - 02:00 Add it to the test tube containing organic compound. Shake the test tube well. Amines have appreciable basicity, so they dissolve in mineral acids. Litmus test Materials required: Organic compound, moist red litmus paper and dropper. Procedure: Take a small quantity of organic compound using a dropper.
• 02:00 - 02:30 Put 1 or 2 drops of the compound onto the moist red litmus paper. Amines turn red litmus blue, indicating it is basic in nature. Azo-dye test Materials required: Organic compound, sodium nitrite, beta-naphthol, distilled water, dilute hydrochloric acid,
• 02:30 - 03:00 dilute sodium hydroxide, ice cold water, test tubes and droppers. Procedure: Take small quantities of organic compound, sodium nitrite and beta-naphthol in tests tubes A, B and C respectively. Using a dropper, add a small quantity of dilute hydrochloric acid to test tube A. Shake the test tube well to dissolve the compound in hydrochloric acid.
• 03:00 - 03:30 Now, add a small quantity of distilled water to test tube B. Shake the test tube well to dissolve sodium nitrite in distilled water to get sodium nitrite solution. Using another dropper, add a small quantity of dilute sodium hydroxide solution to test tube C. Shake the test tube well to dissolve beta-naphthol in dilute sodium hydroxide solution. Cool the test tubes in a beaker containing ice cold water for some time.
• 03:30 - 04:00 Now, add sodium nitrite solution to the organic compound. Primary amine, on reaction with nitrous acid formed from sodium nitrite and hydrochloric acid, gives diazonium salt. Then, add the resulting solution to test tube C containing beta-naphthol solution. The diazonium salt undergoes coupling reaction with beta-naphthol to form a scarlet red coloured
• 04:00 - 04:30 compound called azo dye. Nitrous acid test Materials required Primary, secondary and tertiary amines, sodium nitrite, distilled water, concentrated hydrochloric acid, ice cold water, test tubes, droppers and spatula.
• 04:30 - 05:00 Procedure: Take small quantities of primary, secondary and tertiary amines in test tubes A, B and C respectively. Using a spatula, take a small quantity of sodium nitrite in a test tube. To this add a small quantity of distilled water. Shake the test tube well to dissolve sodium nitrite in distilled water to get sodium nitrite solution. Cool the solution in ice cold water for some time.
• 05:00 - 05:30 Now, using a dropper, add a small quantity of concentrated hydrochloric acid to test tubes A, B and C. Shake the test tubes well to dissolve the compounds in concentrated hydrochloric acid. Cool the test tubes in ice cold water for some time. Now, add sodium nitrite solution to test tubes A, B and C. In test tube A, primary aliphatic amine reacts with nitrous acid, formed from sodium nitrite
• 05:30 - 06:00 and hydrochloric acid, to produce nitrogen gas which is seen as bubbles. In test tube B, secondary amine reacts with nitrous acid to form a yellow oily layer of nitrosamine. In test tube C, tertiary amine reacts with nitrous acid to form soluble nitrite salts. Hinsberg test
• 06:00 - 06:30 Materials required: Primary, secondary and tertiary amines, 25% sodium hydroxide solution, distilled water, benzene sulphonyl chloride, concentrated hydrochloric acid, water in a beaker, test tubes and droppers. Procedure: Take small quantities of primary, secondary and tertiary amines in test tubes A, B and
• 06:30 - 07:00 C respectively. Using a dropper, add a small quantity of 25% sodium hydroxide solution to test tubes A, B and C. Now, add a small quantity of distilled water to each test tube. Using another dropper, add a small quantity of benzene sulphonyl chloride solution to each test tube. Shake the mixture in each test tube for some time. Cool the test tubes in a beaker containing water.
• 07:00 - 07:30 Primary amine reacts with sodium hydroxide and benzene sulphonyl chloride to form soluble sulphonamide salt. Secondary amine reacts with sodium hydroxide and benzene sulphonyl chloride to form insoluble sulphonamide. Tertiary amine will not react with benzene sulphonyl chloride, but it is insoluble in sodium hydoxide.
• 07:30 - 08:00 Using a dropper, add a small quantity of concentrated hydrochloric acid to test tube A. Soluble sulphonamide salt formed will react with hydrochloric acid to form insoluble sulphonamide. Now, add a small quantity of concentrated hydrochloric acid to test tube B. The insoluble sulphonamide formed in test tube B will not react with hydrochloric acid.
• 08:00 - 08:30 Finally, add a small quantity of concentrated hydrochloric acid to test tube C. The insoluble amine reacts with hydrochloric acid to form soluble ammonium salt. Precautions: Handle the organic compound with proper care. Handle hydrochloric acid with proper care because it is highly hazardous.