Outline electrophilic substitution mechanisms.

In the subtopic Benzene and electrophilic substitution (A-level only), this AQA A-Level Chemistry 7405 learning objective focuses on outline electrophilic substitution mechanisms. It belongs to Aromatic chemistry (A-level only), so revision should stay anchored to this exact subtopic rather than drifting into a generic GCSE-level chemistry summary. Approved keywords to use include electrophilic substitution. Benzene. means a cyclic hydrocarbon with the formula C6H6, characterized by its stable ring structure and delocalised electrons Avoid the mistake of students assume the acyl chloride directly reacts with benzene without a catalyst; instead, the Lewis acid (e.g., AlCl3) coordinates to the acyl chloride, forming an acylium ion; the catalyst is essential for generating the electrophile and stabilising the transition state For exam answers, review the specific conditions required for electrophilic substitution reactions, such as temperature and catalysts used in nitration and Friedel-Crafts reactions