Question

Question #24b4c

Answer 1

You'll need some blue litmus and bromine water.

Explanation:

Using the blue litmus you'll notice one of them turns red. This one is the alkyne. Alkynes show acidic nature.

Reason- This is because alkynes have sp hybridisation. Hence, having maximum s character (50%). Having s character maximum, the carbon atom in them is electronegative and so, it attracts the shared electron pair of C-H bond to a greater extent [than alkanes(sp3) or alkenes(sp2)]

Now, having crossed out the alkyne, we're left with the other two. Put bromine water(it's red in colour) in them. One of it will turn colourless. This is alkene.

Reason- Bromine water has bromine, which reacts with the double bonds in alkenes. It breaks the double bonds and fixes itself with the alkene. Now, the colour of bromine water will get discharged, as Bromine has undergone an addition reaction. [As a sidenote, the compound so formed, is called a vicinal dihalide. Also, addition of bromine, is used as a test for unsaturation, since alkenes and alkynes are unsaturated hydrocarbons]

The one that is left now, is alkane. It is neither acidic nor does it react with bromine water(the colour remains intact), since it does not have any double bonds for bromine to react with.