Concept:The hydroxide ion (\( OH^- \)) from NaOH can act either as a Bronsted-Lowry base (removing a proton) or as a Lewis base/Nucleophile (attacking a carbon center).
Solution:- In Aldol Condensation: The \( OH^- \) ion attacks an acidic alpha-hydrogen on the aldehyde/ketone, removing it to form water and an enolate carbanion. Because it accepts a proton, it functions strictly as a Base.
- In Cannizzaro's Reaction: There are no alpha-hydrogens. Therefore, the \( OH^- \) ion directly attacks the electrophilic carbonyl carbon to form a tetrahedral intermediate. Because it donates electrons to form a bond with carbon, it functions as a Nucleophile.
- Thus, the respective functions are Base and Nucleophile.
Why other options are incorrect:The hydroxide anion is negatively charged and electron-rich; it can never act as an electrophile (options A and C). Option D reverses the roles.
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