Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.
(a)

Each of these compounds can react as a nucleophile. In each case, use curved arrows to show how the nucleophile would react with the strong electrophile BF₃.

(a)

(b)

Each of these compounds can react as an electrophile. In each case, use curved arrows to show how the electrophile would react with the strong nucleophile sodium ethoxide, Na^{+ −}OCH₂CH₃.

a.

b. NH₄⁺

Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.

(d)

Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.

(b)

Identify the arrow types that are shown in each of these arrow-pushing mechanisms.

(iv)

Show an arrow-pushing mechanism that forms the product on the right from the reactant at left. Only one arrow is necessary in each reaction. [Don't forget to draw in the lone pairs on this and the next two assessments.]

(a)

Suggest an arrow-pushing mechanism for each of the following acid–base reactions

(c)

Would you expect the following species to be electrophiles or nucleophiles? Some may be both. Explain your answer.

(h)