• Skip to primary navigation
  • Skip to main content
A-Level H2 Chemistry Tuition by 10 Year Series Author

A-Level H2 Chemistry Tuition by 10 Year Series Author

Advanced Chemistry Made Easy

  • Online H2 Chemistry Tuition
  • Success Stories
  • Topics
    • Atomic Structure
    • Chemical Equilibrium
    • Chemical Energetics
    • Reaction Kinetics
    • Chemistry Practicals
    • Mole Calculations
    • Redox Equations & Titrations
    • Organic Chemistry Introductory Topics
    • Organic Chemistry Alkanes
    • Organic Chemistry Alkenes
    • Organic Chemistry Arenes
    • Solubility Product
    • The Gaseous State
  • Books
    • A-Level H2 Chemistry Topical Edition Past Year Series
    • A-Level H2 Chemistry Yearly Edition Past Year Series
  • Videos
  • About Me
  • Contact
  • Show Search
Hide Search
You are here: Home / Organic Chemistry Arenes / Organic Chemistry: 3 Steps in Electrophilic Substitution (Aromatic) Reaction Mechanism

Organic Chemistry: 3 Steps in Electrophilic Substitution (Aromatic) Reaction Mechanism

April 4, 2018 By Sean Chua Leave a Comment

It is important that all JC A-Level H2 Chemistry students understand Electrophilic Substitution (Aromatic) Reaction Mechanism of Arenes. In this YouTube Video, you will learn the step-by-step mechanism with Benzene C6H6 as an example. We always emphasised this mechanism in our recommended H2 Chemistry Tuition Classes in Singapore whereby i’m the principal Chemistry tutor.

Click on the following link for Video on Electrophilic Aromatic Substitution Reaction Mechanism.

H2 Chemistry Video on Electrophilic Aromatic Substitution Reaction Mechanism

Length of video: 9.33 mins

Let’s recap what we have learned from the above video.

First, we look at the meaning of arenes: they are aromatic hydrocarbons and the simplest and most common example is benzene ring, C6H6.

Benzene molecule is planar, symmetrical and non-polar. In the hexagonal ring, there are 3 alternating C=C bonds. Benzene is stabilised as a result of delocalisation of these π electrons in the C=C bonds.

Hence, benzene is resistant to oxidation reaction and electrophilic addition reaction, because these reactions would destroy the cyclic π resonance stabilised system.

Instead, benzene readily undergoes Electrophilic Substitution Reactions in which the ring system is preserved.

Benzene molecule is “electron-rich” and thus reactions of benzene would involve the attack by electrophiles on the π electrons of the benzene ring.

3 Steps in Electrophilic Substitution Reaction Mechanism:

1. Production of electrophile i.e. electron deficient species which are “electron-loving”

2. Formation of carbocation intermediate from the attack of electrophile on the benzene ring

3: Expulsion of H+ ion from the carbocation intermediate to form the aromatic product and the delocalised π system is preserved i.e. benzene ring is re-formed

In the next two blog posts on Organic Chemistry, we will take a look at the two most common reactions (in Singapore’s JC GCE A-Level H2 Chemistry Exam Syllabus Code 9729) involving Electrophilic Substitution Reaction Mechanism of Arenes, namely:

a) Halogenation – Substitution reactions with Chlorine and with Bromine
b) Nitration – Substitution reactions with a Nitration Mixture i.e. Conc. H2SO4 and Conc. HNO3

I hope you find the content easy for your understanding and if you have any questions, leave me a comment below. Feel free to share this blog post with your friends.

Subscribe to my blog to receive 2 updates per month sent to your email!

PS: Under related articles below, there are several blog post discussions and questions related to other Organic Chemistry concepts. You can also do a keyword search using the search box at the top right hand corner.

JC A-Level H2 Chemistry Tuition Testimonial of Cyril Teo HCI 2018
Discover how You Can See Results in Weeks, Stand Proud in front of your naysayers while you learn Chemistry in a Fun, Interactive & Effective way

Call/WhatsApp 98287357 NOW. Time is running out!

Related Articles:

  • Organic Chemistry: Halogenation of Benzene via Electrophilic Aromatic Substitution
  • Organic Chemistry: Nitration of Benzene via Electrophilic Aromatic Substitution Reaction Mechanism
  • Organic Chemistry: Key Concepts in Introductory Topics, Alkanes, Alkenes & Arenes
  • Organic Chemistry: Types of Formulae
  • Organic Chemistry: Electrophilic Addition Mechanism Video
Sean Chua
Sean Chua
Winners Education Centre Pte. Ltd.
Many know me as the Ten Year Series book author for JC A-Level H2 Chemistry and O-Level Pure Chemistry. My 19+ years of coaching experience (since 1999) with more than 1500 students from 180+ JCs and Secondary Schools has allowed me to understand the true reasons why students are not able to perform well in Chemistry. Most importantly, my strength lies in using everyday analogies (even grandmothers can understand!) to simplify abstract concepts. Also, my teaching methodology has been designed to be fun, enjoyable and effective for my students.

If you want to have an enjoyable time learning Chemistry and being motivated to excel in Chemistry, contact me today at 9828 7357

Filed Under: Organic Chemistry Arenes Tagged With: Aromatic Compounds, benzene, Electrophilic Substitution, Organic Chemistry Arenes

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Copyright © 2021 · ALevelH2Chemistry.com · Talk to us at 88290998