L6 Alkenes

Which alkene shows E–Z isomerism?

• 2,3-dimethylbut-2-ene

• 4-methylpent-2-ene

• methylpropene

• pent-1-ene

Which statement about ethene is correct?

• It has no geometric isomers because there is free rotation around the C=C bond.

• It reacts with HBr in a nucleophilic addition reaction.

• It burns in excess oxygen to produce carbon dioxide and water.

• The C=C bond is twice as strong as the C–C bond in ethane.

Which compound reacts with hydrogen bromide to give 2-bromo-3-methylbutane as the major product?

• (CH₃)₂C=CHCH₃

• (CH₃)₂C=CHCH₃

• CH₂=C(CH₃)CH₂CH₃

• (CH₃)₂CHCH=CH₂

General formula of Alkene is 

• C_nH_2n+2
• C_nH_2n
• C_nH_2n+1OH
• C_nH_2n+1COOH

Which has E-Z isomers?

• C₂H₂Br₂

• C₂H₃Br

• C₂H₄Br₂

• C₂H₄Br₂

Which one of the following mechanisms is not involved in the reaction sequence below?

CH₃CH₃ → CH₃CH₂Cl → CH₃CH₂OH → CH₂=CH₂ → CH₃CH₂Br

• electrophilic addition

• electrophilic substitution

• nucleophilic substitution

• free-radical substitution

What is the major product of the reaction between but-1-ene and DBr? (D is deuterium and represents ²H)

• CH₂DCH₂CH₂CH₂Br

• CH₂DCH₂CHBrCH₃

• CH₃CH₂CHBrCH₂D

• CH₃CH₂CHDCH₂Br

What is the IUPAC name of the major product of the reaction between 2-ethylbut-1-ene and hydrogen bromide?

• 1-bromo-2-ethylbutane

• 2-bromo-2-ethylbutane

• 2-bromo-2-methylpentane

• 3-bromo-3-methylpentane

Which statement is not correct about CH₂═C(CH₃)CH₂Br?

• It displays E-Z isomerism.

• It forms an addition polymer.

• It reacts with electrophiles.

• It decolourises bromine water.

In which reaction does the inorganic reagent act initially as an electrophile?

• bromoethane with ethanolic potassium hydroxide

• chloroethane with aqueous sodium hydroxide

• ethane with chlorine

• ethene with concentrated sulfuric acid