Which substitution reaction takes place more rapidly?
a. CH₃CH₂Br + H₂O or CH₃CH₂Br + HO⁻

What is the product of the reaction of bromoethane with each of the following nucleophiles?

a. CH₃CH₂CH₂O⁻

b. CH₃C≡C⁻

What is the product of the reaction of bromoethane with each of the following nucleophiles?

c. (CH₃)₃N

d. CH₃CH₂S^-

Cardura, a drug used to treat hypertension, is synthesized as shown here.

a. Identify the intermediate (A) and show the mechanism for its formation.

Strawberry growers have used large quantities of methyl bromide (b.p. 4 °C) to sterilize the soil before planting their crops. Like some of the freons, methyl bromide can diffuse up into the stratosphere, where it damages the protective ozone layer. Agricultural chemists have suggested using methyl iodide (b.p. 43 °C) as a replacement for methyl bromide. Why is methyl iodide likely to be more toxic to agricultural pests (and people) than methyl bromide? Why is methyl iodide less likely to reach the stratosphere than methyl bromide?

Draw all the products of the following reaction:

Which type of nucleophilic substitution reaction is most likely to occur when pyrimidine dimers in DNA are repaired, potentially leading to mutations that can cause cancer?

In nucleophilic substitution reactions, consider the following pairs of elimination reactions: (1) $E_1$ vs. $E_2$ in a tertiary alkyl halide, and (2) $E_1$ vs. $E_2$ in a primary alkyl halide. For each pair, which elimination reaction is generally faster?

Which of the following is not a nucleophile?