Basic Concepts of Organic Chemistry - Intro to Reaction Mechanisms

Question 1

What is meant by the term reaction mechanism?

Answer 1

Step-by-step description of how a chemical reaction takes place, showing the movement of electrons & the formation of intermediate species.

Question 2

What is the difference between heterolytic & homolytic fission?

Answer 2

• Heterolytic fission involves one (more electronegative) atom taking both electrons from a covalent bond, formating a pos & neg ion.
• Homolytic fission results in each bonded atom taking 1 electron, forming 2 radicals, each with an unpaired electron.

Question 3

What does a curly arrow represent in a reaction mechanism?

Answer 3

Movement of an electron pair, showing how a bond is broken or formed during a chemical reaction.

Question 4

What is an addition reaction? (With an example)

Answer 4

• Reaction in which 2 reactants combine to form 1 larger product.
• e.g. C₂H₄ + Br₂ → C₂H₄Br₂

Question 5

What is an elimination reaction? (With an example)

Answer 5

• Removal of a small molecule from a larger one, resulting in the formation of 2 products.
• e.g. C₂H₅OH → C₂H₄ + H₂O

Question 6

What is a substitution reaction? (With an example)

Answer 6

• An atom/group of atoms is replaced by a different atom/group of atoms in a molecule.
• e.g. CH₄ + Cl₂ → CH₃Cl + HCl