(i) Ethylbenzene gives benzoic acid on oxidation with `KMnO_(4)` while o-xylene gives phthalic acid.
(II) Styrene, Having a double bound in the side-chain, gives the following two tests :
(a) It decolourises purple colour of dilute cold `KMnO_(4)` solution. Brown precipitate of `MnO_(2)` is formed. This test is not given by ethylbenzene.
(b) Styrene repidly dicolourises red colour of bromine in `C CI_(4)`. Ethylbenzene does not decolourise under this condition.
`C_(6)H_(5)CH=CH_(2)+Br_(2)tounderset("Coloureless")(C_(6)H_(5)CHBrCH_(2)Br)`
However, ethylbenzene reacts wiith bromine at thgh temperature or in presence of UV light.
(iii) Phenyl acetylene gives a precipitate with ammoniacal silver nitrate solution. Styrene does not react.
`C_(6)H_(5)-C-=CH+AgNO_(3)+NH_(4)OHtounderset(("ppt"))(C_(6)H_(5)-C-=Ag+NH_(4)NO_(3)+H_(2)O)`
(iv) Toluene is easily oxidised to benzaldegyde with `CrO_(2)CI_(2)` or benzoic acid with `KMnO_(4)`.
Benzene is quite stable and does not undergo oxidation with `CrO_(2)CI_(2)" or "KMnO_(4)`.
