Chemistry 1B PASS W7

In a nucleophilic substitution reaction of haloalkanes, what does the nucleophile attack?

• The hydrogen atom

• The carbon bearing the halogen

• The carbon bearing the hydrogen

• The halogen atom

What causes the bond between carbon and halides to be polarised in nucleophilic substitution reactions?

• The difference in size

• The difference in charge

• The difference in electronegativity

• The difference in mass

What is the characteristic feature of the energy profile for an SN2 reaction?

• two transition states

• single transition state

• no transition state

• multiple intermediates

In the context of the SN2 mechanism, what does the term 'backside attack' refer to?

• The nucleophile attacks the same side as the leaving group

• The nucleophile attacks the opposite side of the leaving group

• The nucleophile attacks from above the molcecule

• The nucleophile attacks from below the molecule

What is the rate determining step in an SN1 reaction?

• Dissociation of the leaving group

• Formation of the product

• Attack of the nucleophile

• Formation of the carbocation intermediate

What is the stereochemical outcome of an SN2 reaction?

• Retention of configuration

• Racemic mixture

• Inversion of configuration

• No change in configuration

Which type of isomers are related to chirality?

• Stereoisomers

• Geometrical isomers

• Optical isomers

• Diastereoisomers

What are the isomers called that are non-superimposable mirror images of each other?

• enantiomers

• geometrical isomers

• diastereoisomers

• optical isomers

When does chirality occur?

• When there are two different substituents around a C atom

• When there are three different substituents around a C atom

• When there are four different substituents around a C atom

• When there are no substituents around a C atom

What are the necessary conditions for an object to be chiral?

• Two dimensions, plane of symmetry, no stereogenic centres

• Three dimensions, no plane of symmetry, possible stereogenic centres

• Three dimensions, plane of symmetry, no stereogenic centres

• Two dimensions, no plane of symmetry, possible stereogenic centres