Octane number of petrol can be improved by admixing it with which of the following chemicals?

• Et₄Pb

• CH₃OC(CH₃)₃

• Both (a) and (b)

• Pyrene

The cumulated alkadiene is

The number of possible alkynes with molecular formula C₅H₈ is

• 1

• 3

• 5

• 8

In the following reaction, number of possible structure is

• 1

• 2

• 5

• 6

Which one of the following represents the major product of the reaction of benzene with 2, 2-dimethylpropyl chloride in presence of anhydrous aluminium chloride?

• 2, 2-dimethylpropylbenzene

• 1, 1-dimethylpropylbenzene

• 1, 2-dimethylpropylbenzene

• 1, 2-dimethyl-1-propenylbenzene

An alkyl bromide is formed as the major product on reaction of 3-methyl-2-butene with hydrobromic acid under thermodynamic conditions. Which of the following is the correct IUPAC name of this product?

• 2-bromo-3-methylbutane

• 1-bromo-3-methylbutane

• 2-bromo-2-methylbutane

• 1-bromo-3-methyl-2-butene

The IUPAC name of 

   is

• 4-bromo-2-chloro-5-iodo-1-fluorobenzene

• 2-carbamoylhex-3-enal

• 1-bromo-2-chloro-3-fluoro-6-iodobenzene

• 2-bromo-1-chloro-5-fluoro-3-iodobenzene

In Zeigler Natta polymerisation of ethylene, the active species is

• AlCl₃

• Et₃Al

• CH₂CH₂

• Ti³⁺

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