AQA A-Level Chemistry 7405
Atomic Structure
Amount of Substance
Bonding
Energetics and Thermodynamics
Kinetics
Chemical Equilibria
Redox and Electrochemistry
Acids and Bases
Periodicity and Group Chemistry
Period 3 Elements and Their Oxides
Transition Metals
Introduction to Organic Chemistry
Hydrocarbons
Halogenoalkanes, Alcohols and Organic Analysis
Carbonyls, Carboxylic Acids and Derivatives
Aromatic Chemistry and Amines
Polymers, Amino Acids, Proteins and DNA
Organic Synthesis, NMR and Chromatography
Halogenoalkanes, Alcohols and Organic Analysis
Effect of Bond Enthalpy on Reaction Rate
- 3 things to know
- Papers 2 and 3
Overview
Why iodoalkanes hydrolyse fastest, and why bond enthalpy matters more than polarity here.
What you need to know
Answer each one before you reveal it.
Why do halogenoalkanes with different halogens react at different rates with nucleophiles?
What is the trend in carbon-halogen bond enthalpies from C-F to C-I?
Questions from this subtopic
Each one with the model answer underneath.
- 1
Why do halogenoalkanes with different halogens react at different rates with nucleophiles?
Model answer
The carbon-halogen bond must be broken during the reaction, and different carbon-halogen bonds have different bond enthalpies.
- 2
What is the trend in carbon-halogen bond enthalpies from C-F to C-I?
Model answer
Bond enthalpy decreases from C-F to C-I (C-F is strongest, C-I is weakest).
- 3
Which carbon-halogen bond is the strongest?
Model answer
The C-F bond.
- 4
Which carbon-halogen bond is the weakest?
Model answer
The C-I bond.
- 5
How does bond enthalpy relate to the ease of breaking a carbon-halogen bond?
Model answer
Weaker bonds (lower bond enthalpy) are easier to break, requiring less energy.
- 6
Which halogenoalkane reacts fastest with aqueous hydroxide ions: fluoroalkane, chloroalkane, bromoalkane, or iodoalkane?
Model answer
Iodoalkane.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Halogenoalkanes, Alcohols and Organic Analysis, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.