21.

Fool's gold is

• Cu₂S

• FeS₂

• Al₂O₅

• CuFeS₂

Which of the following is not a isomer of pentane?

• n-pentane

• 2, 2-dimethyl 1-propane

• 2, 3-dimethyl 1-butane

• 2-methyl 1-butane

The oxidation number of C atom in CH₂Cl₂ and CCl₄ are respectively

• -2 and -4

• 0 and -4

• 0 and 4

• 2 and 4

Which of the following compound is not aromatic?

• 1,3-cyclobutene

• Pyridine

• Furane

• Thiophene

Which of the following group is sharp -ortho and -para directive?

• -C₆H₅

• -OH

• CH₃

• -Cl

By which of the following process hydrocarbons are found from petroleum?

• Combustion

• Fractional distillation

• Addition

• All of the above

The reaction of sodium acetate and sodalime gives

• butane

• ethane

• methane

• propane

The false statement regarding alkane is

• this does not perform polymerization reaction

• this does not gives elimination reaction

• it does not disappear the colour of dilute KMnO₄ solution

• it does not decolourise bromine water

Which of the following aromatic compound gives sulphonation reaction very easily?

• Chlorobenzene

• Nitrobenzene

• Toluene

• Benzene

Which of the following on combustion gives maximum energy?

• Ethane

• Propane

• Methane 

• Butane