Nucleophilic Substitution 5N1 and 5N2 Summary Questions
t Isa nucleophile? Give some examples of nucleophiles‘.
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Write the general equation for Nucleophilic Substitution (showing the nucleophile and Halogen (X))
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What'Is heterolytic fission?
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tep, 1 (prImary)... In the dIagrams below, show the m o v e m e n t of the electron pairs with the curly arrow...
Nucleophile attacking
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Formation of alcohol and the release of
halogenoalkane from the back
nucleophile and halogen both
the leaving group (halide)
attached by weak bonds)... Show the
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Why (tees the 5N2 mechanism favour primary halogenoalkanes and n o t tertiary? (Think
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Explain why the SN2 mechanism is bimoiecuiar Write the rate equation for this mechanism
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What happens to the arrangement of the a t o m s around the carbon a t o m after 5N2?
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5N1, 2 Step, 3° (tertiary)... in the diagrams below, show the m o v e m e n t of the electron pairs with the curly arrow...
Step 1: Heterolytic fission of the carbon‐haiogen bond
Step 2: Carbocation intermediate attacked by nucleophiie
(ionizes the halogenoaikane).
leading to n e w bond...
Halide ion will leave, producing a carbocation
intermediate.
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The presence of 3 alkyi groups on the tertiary haiogenoalkane has what effect on the carbocation?
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Explain why the 5N1 mechanism is unimoiecuiarI Wr i t e the r a t e equation for this mechanism.
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Which nucleophilic substitution mechanism do 2° (secohdary) haldgenoalkanes undergo?
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What are the three factors that affect the r a t e
of nucleophiiic substitution?
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Give the order
of rates according to the type of halogenoalkanei Start with the fastesthalogenoatkane and annotate
which SNmechanism is applicable under each halogenoalkanei
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Explain how the influence of the leaving group involves:
(a) polarity of the carbon‐halogen bond
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Describe which (polarity or strength) of the carbon-haiogen bond is the dominant factor for determining rate.
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Explain which solvents (polar & protic/polar & aprotic) are favoured by:
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Explain the statement above using understanding about:
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10, 20 and 30halogenoalkanes
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the mechanisms they favour
which is the best carbon~halogen bond (in t e r m s of rate)
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the Choice of solvent that each mechanism favours
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