Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download distinguishing between organic compounds
Document related concepts
no text concepts found
Transcript
Distinguishing between organic compounds Organic substances can look the same – you must be able to distinguish between common compounds by comparing their properties and performing simple tests. 12 Chemistry 2.2 organic chemistry CR 07 Common compounds Alcohols, carboxylic acids, alkanes, alkenes, esters - all colourless liquids! How could you distinguish between them?? 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 1. 2. 3. 4. 5. 6. Questions you could ask: Is it flammable? Is it miscible with water? Does it react with an oxidant? Does it react with halogens? Does it smell? Does it behave as an acid? 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 1. Mix with water Miscible Not miscible - 2 layers Alcohol Alkane (short chain) Alkene Carboxylic Ester acid 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 2. Add magnesium Reaction No reaction Carboxylic acid Fizzing and litmus will go pink Alkane Alkene Ester Alcohol 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 3. Add Br2 Reaction orange Alkane slow – requires UV light Alkene fast – no catalyst required No reaction Carboxylic acid Ester Alcohol 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 4. Add Cr2O72-/H+ Reaction orange green Alcohol for primary alcohols No reaction Carboxylic acid Ester Alkene Alkane 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 5. Carefully smell Fruity smell Ester * Carboxylic acid may smell unpleasant Not fruity Carboxylic acid Alkene Alkane Alcohol 12 Chemistry 2.2 organic chemistry CR 07 Alcohols, carboxylic acids, alkanes, alkenes, esters 6. Carefully ignite – not necessary as other tests will identify them flammable Ester volatile Alkene sooty orange flame Alkane clean burning Alcohol clean burning Not flammable Carboxylic acid 12 Chemistry 2.2 organic chemistry CR 07
Related documents