Which of the following species acts exclusively as an electrophilic reagent? — Reaction Mechanism Chemistry Question

💡 Solution & Explanation

Electrophiles are electron-deficient species that accept electron pairs during chemical reactions. The nitronium ion ($NO_2^+$) is positively charged and clearly electron-deficient. $H_2O$, $OH^-$, and $NH_3$ possess unshared electron pairs and act as nucleophiles.