Tests for Organic Functional Groups OCR Chemistry A 0.0 / 5 ? ChemistryReactionsFunctional GroupsA2/A-levelOCR Created by: Oliviali11yCreated on: 20-03-19 10:27 What are the reagents and observations when testing for alkenes? Add a few drops of bromine water and shake well. If an alkene is present the bromine water decolourises 1 of 14 What are the reagents and obervations when testing for haloalkanes? Add aqueous silver nirate and ethanol. White precipitate-silver chloride, Cream precipitate-Silver bromide, Yellow precipitate-Silver iodide 2 of 14 What are the reagents and observations when testing for a carbonyl group? Add 2,4-DNP (Brady's Reagent). A yellow or orange preccipitate will form if an aldehyde or ketone is present 3 of 14 What are the obervations when Fehling's solution is added to an aldehyde? The blue solution forms a dark red precipitate 4 of 14 What are the obervations when Tollen's reagent is added to an aldehyde? A silver mirror is produced 5 of 14 What are the obervations when acidified potassium dichromate is added to an aldehyde? The orange solution turns green 6 of 14 What are the obervations when universal indicator or a pH probe is used on aliphatic carboxylic acids? The pH is for a weak acid 7 of 14 What are the obervations when a reactive metal(eg. Mg) or metal carbonate (eg.calcium carbonate) is reacted with an aliphatic carboxylic acids? Effervescene 8 of 14 What are the obervations when universal indicator or a pH prode is added to phenol? pH for a weak acid 9 of 14 What are the obervations when a carbonate is added to phenol? There is no reaction so there is no effervescene 10 of 14 What are the obervations and products when acidified potassium dichromate is added to a primary alcohol? Colour change from orange to green as an aldehyde is formed and then a carboxylic acid 11 of 14 What are the obervations and products when acidified potassium dichromate is added to a secondary alcohol? They are oxidised to a ketone and the colour changes from orange to green 12 of 14 What are the obervations and products when acidified potassium dichromate is added to a tertiary alcohol? They cannot be oxidised so there is no obsservable colour change 13 of 14 What are the observations and products when an alcohol is warmed with an equal volume of a carboxylic acid and a few drops of sulfuric acid? Sweet smell of an ester after a short time 14 of 14
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