Nucleophilic substitution

P2 June 2017 Q1 Hi there... This is the first post in a series looking at past AQA A-level Chemistry questions. I wanted to go beyond the answers and focus on thought processes, ideas and tips that will help in examinations. The series will help you to spot weaknesses and help with revision, or it can serve as addenda to your notes. If you haven't gone through the paper, please look up the questions at www.aqa.org.uk, or click the direct link below, and have a go... AQA A-level CHEMISTRY Paper 2

A guide to the two pathways for nucleophilic substitution. SN1 Mechanism The mechanism involves two-steps. With a tertiary halide: In the first step, which is the slow step, the C-Cl bond will break and both electrons will go to Cl. A carbocation intermediate and Cl- form. The second (fast) step sees the hydroxide, OH-, attacking the carbocation and forming the alcohol. In the slow step, there is only one halogenoalkane, hence the rate is first order with respect to halogenoalkane and zero order

P2 June 2017 Q11 Part of a series looking at past AQA A-level Chemistry questions with a focus on better performance in examinations. If you haven't gone through the question/paper, click the direct link below, and have a go... AQA A-level CHEMISTRY Paper 2 Organic and Physical Chemistry Monday 19 June 2017 Question 11 is about amines An 11-mark, 2-part extended answer question Question 11 The base strength has everything to do with the lone pair on the nitrogen - how available the lone pair is.