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    WJEC CH4 Compound Tests

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    Bhavesh Tailor
    This document provides instructions for chemical tests to identify various functional groups, including aldehydes, ketones, carboxylic acids, phenols, amines, amides, alcohols, alkenes, halogenalkanes, esters, nitriles, amino acids, and methyl ketones. It describes several reagents and their reactions, including Tollen's reagent and Fehling's solution for aldehydes, Brady's reagent for aldehydes and ketones, sodium carbonate for carboxylic acids, iron(III) chloride for phenols, nitrous acid for primary/secondary/tertiary amines, sodium hydroxide for amides and nitriles,

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    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd

    WJEC CH4 Compound Tests

    Uploaded by

    Bhavesh Tailor
    205 views2 pages
    This document provides instructions for chemical tests to identify various functional groups, including aldehydes, ketones, carboxylic acids, phenols, amines, amides, alcohols, alkenes, halogenalkanes, esters, nitriles, amino acids, and methyl ketones. It describes several reagents and their reactions, including Tollen's reagent and Fehling's solution for aldehydes, Brady's reagent for aldehydes and ketones, sodium carbonate for carboxylic acids, iron(III) chloride for phenols, nitrous acid for primary/secondary/tertiary amines, sodium hydroxide for amides and nitriles,

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    WJEC

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    This document provides instructions for chemical tests to identify various functional groups, including aldehydes, ketones, carboxylic acids, phenols, amines, amides, alcohols, alkenes, halogenalkanes, esters, nitriles, amino acids, and methyl ketones. It describes several reagents and their reactions, including Tollen's reagent and Fehling's solution for aldehydes, Brady's reagent for aldehydes and ketones, sodium carbonate for carboxylic acids, iron(III) chloride for phenols, nitrous acid for primary/secondary/tertiary amines, sodium hydroxide for amides and nitriles,

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    205 views2 pages

    WJEC CH4 Compound Tests

    Uploaded by

    Bhavesh Tailor
    This document provides instructions for chemical tests to identify various functional groups, including aldehydes, ketones, carboxylic acids, phenols, amines, amides, alcohols, alkenes, halogenalkanes, esters, nitriles, amino acids, and methyl ketones. It describes several reagents and their reactions, including Tollen's reagent and Fehling's solution for aldehydes, Brady's reagent for aldehydes and ketones, sodium carbonate for carboxylic acids, iron(III) chloride for phenols, nitrous acid for primary/secondary/tertiary amines, sodium hydroxide for amides and nitriles,

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
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    GENERAL CERTIFICATE OF EDUCATION TYSTYSGRIF ADDYSG GYFFREDINOL

    CH4

    AS/A2 CHEMISTRY CH4 - Compound Tests 1. Aldehydes Tollens Reagent - Mix and heat the compound under test with Tollens (which contains the Diamminesilver(I) ion, [NH3)2Ag]). If an aldehyde is present, a silver mirror result will be formed on the inside of the test tube. Fehlings Reagent - The substance under test is warmed with equal volumes of aqueous copper(II) sulfate and sodium potassium tartrate dissolved in aqueous sodium hydroxide. If an aldehyde is present, a reddish colour will develop as copper(I) oxide, Cu2O, is formed. Ketones do not give this reaction. Bradys Reagent - When an aldehyde is reacted with 2,4-Dinitrophenylhydrazine a yellow/orange precipitate of the corresponding hydrozone is formed as a precipitate. 2.Ketones Bradys Reagent - When an ketone is reacted with 2,4-Dinitrophenylhydrazine a yellow/orange precipitate of the corresponding hydrozone is formed as a precipitate. 3.Carboxylic Acids Carboxylic Acids will react with sodium carbonate or aqueous sodium hydrogen carbonate and CO2 gas will be evolved. 4.Phenols Phenol will react with aqueous Iron (III) Chloride and form a purple colour. 5.Amines Primary Amines react with Nitrous Acid (HNO2) and a burst of colourless Nitrogen gas is evolved. Secondary Amines react with Nitrous Acid (HNO2) to produce a yellow carcinogenic oil. Tertiary Amines remain colourless with Nitrous Acid (HNO2). 6.Amides When you add sodium hydroxide solution to an Amide, it gives off ammonia on heating. You can recognise the ammonia as it has a pungent odor.
    1

    7. Alcohols When Primary and Secondary Alcohols are warmed with acidified potassium dichromate the solution will change colour from Orange to Green. When the same test is applied to Tertiary Alcohols no colour change is observed. Primary Alcohols can be distinguished from Secondary Alcohols by oxidizing them and testing for the aldehyde or ketone product with Tollens. 8. Alkenes When an Alkene is shaken with Bromine water is decolourises, changing from Brown to Colourless.

    9. Halogenalkanes Silver Nitrate - The halogenoalkane is warmed with sodium hydroxide solution in a mixture of ethanol and water. The mixture is acidified by adding dilute nitric acid. Then silver nitrate solution is added. - If Chloride ions are present then a white precipitate forms, - If Bromide ions are present then a cream precipitate forms, - If Iodide ions are present then a primrose yellow precipitate forms. 10. Esters Esters give a sweet/antiseptic smell. 11. Nitriles When you add sodium hydroxide solution to a Nitrile, it gives off ammonia on heating. You can recognise the ammonia as it has a pungent odor. 12. Amino Acids/Proteins When a sample of Dilute amino acid or protein is boiled with Ninhydrin, and Blue colour appears. 13.Iodoform Test When a Methyl Ketone or alcohol that can be oxidized to a Methyl Ketone is added to an aqueous solution of Iodine and Sodium Hydroxide a pale yellow precipitate will be seen.

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