Question 1
By what mechanism is the reaction shown likely to occur?
![](data:image/png;base64, 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)
◦ S
N1 (major) and/or E1 (minor)
◦ S
N2 (major) and/or E2 (minor)
◦ E2 only
◦ E1 only
◦ It is impossible to tell from the information given.
Question 2
By what mechanism is the reaction shown likely to occur?
![](data:image/png;base64, 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)
◦ S
N1 or E1
◦ E1 or E2
◦ S
N2
◦ S
N1
◦ S
N2 or E2