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Which tests could be used to distinguish between alkanes and alkenes?
Use bromine water (Br2) or acidified permanganate (H+/MnO4-) With permanganate: add the permanganate to the alkane and no reaction will occur, add the permanganate to the alkene and you will form a diol the solution will also turn from purple to colourless. With bromine water: add the bromine water to the alkane (plus you need sunlight) and you get a substitution reaction, this is a slow reaction. Add the bromine water to the alkene and you get an immediate addition reaction (this one does not need sunlight). When bromine water reacts with an alkene it is decolourised, the reddish brown bromine water turns from brown to colourless. This is because alkenes are unsaturated and contain a carbon to carbon double bond. If you did the bromine water test in a dark place say a cupboard then the alkene would decolourise but the alkane wouldn't because it needs UV/sunlight in order to react. in practice the cupboard is not necessary as the speed of decolourisation is so much faster with the alkene.
What test can you carry out to differentiate between two test tubes one containing propane and propene?
Propene is an alkene, whereas propane is an alkane. Thus, propene is an unsaturated molecule, having a carbon-carbon double bond. If you add bromine water, an aqueous solution of bromine, to the test tubes, you can tell which is propene, the alkene. The bromine reacts with and saturates the double bonds in alkenes, and so decolourises. The bromine does not decolourise when added to an alkane as it does not react. So, in conclusion:Add bromine water (brown) to the test tubesIf the bromine water stays brown, the test tube contains propaneIf the bromine water goes colourless, the test tube contained propene.
Which gas would decolourise bromine water?
Any Halogen gas; F2, Cl2,Br2,I2....
What color does bromine water go when it reacts with an alkene?
Firstly, there is a discharge of reddish brown colour due to bromine which then turns colourless.
What test is used to distinguish between ethene and methane?
Ethene is an unsaturated substance since it is alkene and has one double bond, we can use bromine water to test ethene. Yellow bromine water turns colourless if the substance is ethene. If it is methane which is alkane ( not alkene ), bromine will stay yellow.
What alkene decolourises bromine water?
All alkenes decolourise bromine water.
What simple chemical test will distinguish an alkene from an alkane?
Test both in bromine water. The unsaturated alkene will decolourise the bromine water.
What changes in color occur when bromine or KMnO4 reacts with an alkene?
The purple KMnO4 is decolourise
What you would see when orange bromine water is shaken with propene?
Bromine water is a dilute solution of bromine that is normally orange-brown in colour, but becomes colourless when shaken with an alkene. Alkenes can decolourise bromine water, while alkanes cannot.
Why benzene does not decolourise bromine water?
Benzene will not decolourise bromine water as it does not undergo addition reaction. It is highly saturated due to presence electron cloud above and below it.
Why does alkyne decolourise bromine water?
The alkyne reacts with bromine removing it from the aqueous solution.
How much ethene is needed to decolourise bromine water?
36ads
Would ethane decolorise bromine water?
Actually no...ethane ( Alkane class in general ) decolourise bromine water due to the absence of the double bond ( C=C )...so ethene (alkenes in general ) will decolourise the bromine water..
Chemical reaction between phenol and bromine water?
it cant decolourise
Which tests could be used to distinguish between alkanes and alkenes?
Use bromine water (Br2) or acidified permanganate (H+/MnO4-) With permanganate: add the permanganate to the alkane and no reaction will occur, add the permanganate to the alkene and you will form a diol the solution will also turn from purple to colourless. With bromine water: add the bromine water to the alkane (plus you need sunlight) and you get a substitution reaction, this is a slow reaction. Add the bromine water to the alkene and you get an immediate addition reaction (this one does not need sunlight). When bromine water reacts with an alkene it is decolourised, the reddish brown bromine water turns from brown to colourless. This is because alkenes are unsaturated and contain a carbon to carbon double bond. If you did the bromine water test in a dark place say a cupboard then the alkene would decolourise but the alkane wouldn't because it needs UV/sunlight in order to react. in practice the cupboard is not necessary as the speed of decolourisation is so much faster with the alkene.
Why does bromine water decolourise with SO2?
It's because, bromine water, being a good oxidising agent oxidises SO2 to H2SO4.
Will saturated oils decolourise bromine?
No, unsaturated oils and fats (sunflower oil, olive oil) decolourise when reacted with bromine
