KMnO4 (acidic/alkaline) is not decolourised by from Chemistry Hy

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 Multiple Choice QuestionsMultiple Choice Questions

461.

LPG mainly contains :

  • ethyne

  • butane

  • methane

  • ethane


462.

Alkyl halides react with dialkyl copper reagents to give

  • alkenyl halides

  • alkanes

  • alkyl copper halides

  • alkenes


463.

Amongst the following compounds, the optically active alkane having lowest molecular mass is

  • CH3-CH2-CH2-CH3

  • CH3-CH2-CH(CH3)-CH3

  • CH3-CH2-C≡CH


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464.

KMnO4 (acidic/alkaline) is not decolourised by

  • Mohr salt

  • Oxalic acid

  • Benzene

  • Propene


C.

Benzene

The acidic/ alkaline KMnO4 is not decolourised by the aromatic compounds due the delocalisation of π electrons in the nucleus.

Aromatic compounds which have = or ≡ bond in the side chain decolourise acidic/ alkaline KMnO4. Benzene does not decolourise the acidic/ alkaline KMnO4 due to the delocalisation of electrons.

While propene decolourised the alkaline KMnO4 due to the presence of = bond. Ferrous ammonium sulphate and oxalic acid decolourised the KMnO4 in acidic medium.

2KMnO4 + 10FeSO4 + 8H2SO4 → K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O

2KMnO4 + 5C2H2O4 + 3H2SO4 → K2SO4 + 2MnSO4 + 10CO2 + 8H2O


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465.

When acetylene is passed through dil H2SO4, in presence of HgSOthe compound formed is

  • ether

  • acetaldehyde

  • acetic acid

  • ketone


466.

CH3CH2CH3 400-600°C X + Y

X and Y are

  • hydrogen

  • methane

  • hydrogen

  • ethylene


467.

How many π bonds are present in naphthalene?

  • 4

  • 5

  • 6

  • 7


468.

The number of possible alkyns with molecular formula C5H8 is

  • 3

  • 4

  • 5

  • 6


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469.

Ammoniacal silver nitrate form a white precipitate easily with

  • CH3C≡CH

  • CH3C≡C-CH3

  • CH3CH=CH2

  • CH2=CH2


470.

Which of the following compounds would have the highest boiling point ?

  • CH3CH2CH2CH3

  • CH3NH2

  • CH3OH

  • CH2F2


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