How many delocalised π-electrons are there in the following compound?

• 1

• 2

• 3

• 6

Which of the following is an anti-knocking compound?

• TEL

• LTC

• Freon

• Gasoline

A compound contains two dissimilar asymmetric C-atoms. The number of optical isomers is

• 1

• 2

• 4

• 8

Which of the following is the strongest nucleophile?

• OH^-

• CH₃O^-

• CH₃S^-

• C₂H₅O^-

The incorrect statements among the following is

• the first ionisation potential of Al is less than the first ionisation potential of Mg

• the second ionsiation potential of Mg is lower than the second ionsiation potential of Na

• the first ionisation potential of Na is less than the first ionisation potential of Mg

• the third ionisation potential of Mg is greater than the third ionisation potential of Al

26.

When the sample of copper with zinc impurity is to be purified by electrolysis, the appropriate electrodes are

•  

  Anode	Cathode
  Pure zinc	pure copper

•  

  Anode	Cathode
  impure zinc	pure copper

•  

  Anode	Cathode
  impure zinc	impure sample

•  

  Anode	Cathode
  impure sample	pure copper

Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species?

• Cl <F <S <CO

• O <S <F <Cl

• S <O <Cl <F

• F <Cl <O <S

Acidified solution of chromic acid on treatment with H₂O₂ yields

• CrO₃ + H₂O + O₂

• Cr₂O₃ + H₂O + O₂

• CrO₅ + H₂O

• H₂Cr₂O₇ + H₂O + O₂

Bleaching action of bleaching powder is due to

• Cl

• O

• Ca

• Cl₂

Which of the following is an alum?

• Na·AlO₂

• Na₂SO₄·Al₂(SO₄)₃·24H₂O

• KCl·MgCl₂·6H₂O

• FeSO₄ ·(NH₄)₂SO₄·6H₂O