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Nucleophilic substitution

How Halogenoalkanes React and Affect Our Planet

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How Halogenoalkanes React and Affect Our Planet
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Eliza

@3liza

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A comprehensive guide to nucleophilic substitution in halogenoalkanes, their properties, reactions, and environmental impact of halogenoalkanes and CFCs. This essential chemistry topic covers the formation, reactions, and applications of halogenoalkanes, including their role in environmental concerns and industrial uses.

• Halogenoalkanes are compounds where hydrogen atoms in alkanes are replaced by halogens, creating polar covalent bonds
• Key reactions include hydrolysis of halogenoalkanes with sodium hydroxide and elimination reactions
• Environmental concerns focus heavily on CFC impacts on the ozone layer
• Industrial applications include use as solvents, anaesthetics, and historically as refrigerants
• Chemical behavior varies based on the specific halogen present, affecting bond strength and reaction rates

15/04/2023

79

Halogenoalkanes > Analkane where one or more hydrogen atoms have been replaced by a halogen. so it contains at least one polar covalent bond

View

Page 2: Applications and Environmental Impact

The second page delves into the practical applications of halogenoalkanes and their significant environmental implications, particularly focusing on CFCs and their alternatives.

Highlight: Halogenoalkanes serve as versatile solvents due to their unique molecular structure, containing both polar and non-polar sections.

Example: CFCs undergo a chain reaction in the upper atmosphere: CCl₂F₂ → Cl° + CClF₂°, followed by Cl° reacting with ozone in a destructive cycle.

Definition: CFCs (chlorofluorocarbons) are compounds that were widely used as refrigerants but are now known to damage the ozone layer.

Vocabulary: Bond strength, measured in kJ mol⁻¹, varies significantly between different bonds (C-H: 413, C-Cl: 328, C-F: 485), affecting their stability and reactivity.

Quote: "The use of halogenoalkanes is limited due to the environmental effects. Polychloroalkanes are toxic and CFCs damage the ozone layer, particularly over Arctic and Antarctic."

Halogenoalkanes > Analkane where one or more hydrogen atoms have been replaced by a halogen. so it contains at least one polar covalent bond

View

Page 1: Halogenoalkane Structure and Reactions

The first page introduces the fundamental concepts of halogenoalkanes and their reactions. The text explains nucleophilic substitution reactions and the process of hydrolysis under various conditions.

Definition: Halogenoalkanes are alkanes where one or more hydrogen atoms have been replaced by a halogen, resulting in at least one polar covalent bond.

Highlight: The hydrolysis reaction involves heating halogenoalkanes under reflux with sodium or potassium hydroxide solution, using water as a high-polarity solvent.

Vocabulary: Reflux refers to a process of continuous evaporation and condensation, utilizing a vertical condenser to prevent loss of volatile substances.

Example: During the silver nitrate test for halogenoalkanes, a substitution reaction produces halide ions, which then react with silver nitrate to form distinctive precipitates - white for chlorine, cream for bromine, and yellow for iodine.

Definition: Electronegativity decreases as halogen size increases, affecting bond strength and reaction rates in substitution reactions.

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Subjects

/

Chemistry

/

Organic chemistry

/

Halogenoalkanes

/

Nucleophilic substitution

How Halogenoalkanes React and Affect Our Planet

user profile picture

Eliza

@3liza

·

32 Followers

Follow

A comprehensive guide to nucleophilic substitution in halogenoalkanes, their properties, reactions, and environmental impact of halogenoalkanes and CFCs. This essential chemistry topic covers the formation, reactions, and applications of halogenoalkanes, including their role in environmental concerns and industrial uses.

• Halogenoalkanes are compounds where hydrogen atoms in alkanes are replaced by halogens, creating polar covalent bonds
• Key reactions include hydrolysis of halogenoalkanes with sodium hydroxide and elimination reactions
• Environmental concerns focus heavily on CFC impacts on the ozone layer
• Industrial applications include use as solvents, anaesthetics, and historically as refrigerants
• Chemical behavior varies based on the specific halogen present, affecting bond strength and reaction rates

15/04/2023

79

 

12

 

Chemistry

0

Halogenoalkanes > Analkane where one or more hydrogen atoms have been replaced by a halogen. so it contains at least one polar covalent bond

Page 2: Applications and Environmental Impact

The second page delves into the practical applications of halogenoalkanes and their significant environmental implications, particularly focusing on CFCs and their alternatives.

Highlight: Halogenoalkanes serve as versatile solvents due to their unique molecular structure, containing both polar and non-polar sections.

Example: CFCs undergo a chain reaction in the upper atmosphere: CCl₂F₂ → Cl° + CClF₂°, followed by Cl° reacting with ozone in a destructive cycle.

Definition: CFCs (chlorofluorocarbons) are compounds that were widely used as refrigerants but are now known to damage the ozone layer.

Vocabulary: Bond strength, measured in kJ mol⁻¹, varies significantly between different bonds (C-H: 413, C-Cl: 328, C-F: 485), affecting their stability and reactivity.

Quote: "The use of halogenoalkanes is limited due to the environmental effects. Polychloroalkanes are toxic and CFCs damage the ozone layer, particularly over Arctic and Antarctic."

Halogenoalkanes > Analkane where one or more hydrogen atoms have been replaced by a halogen. so it contains at least one polar covalent bond

Page 1: Halogenoalkane Structure and Reactions

The first page introduces the fundamental concepts of halogenoalkanes and their reactions. The text explains nucleophilic substitution reactions and the process of hydrolysis under various conditions.

Definition: Halogenoalkanes are alkanes where one or more hydrogen atoms have been replaced by a halogen, resulting in at least one polar covalent bond.

Highlight: The hydrolysis reaction involves heating halogenoalkanes under reflux with sodium or potassium hydroxide solution, using water as a high-polarity solvent.

Vocabulary: Reflux refers to a process of continuous evaporation and condensation, utilizing a vertical condenser to prevent loss of volatile substances.

Example: During the silver nitrate test for halogenoalkanes, a substitution reaction produces halide ions, which then react with silver nitrate to form distinctive precipitates - white for chlorine, cream for bromine, and yellow for iodine.

Definition: Electronegativity decreases as halogen size increases, affecting bond strength and reaction rates in substitution reactions.

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Knowunity is the #1 education app in five European countries

Knowunity has been named a featured story on Apple and has regularly topped the app store charts in the education category in Germany, Italy, Poland, Switzerland, and the United Kingdom. Join Knowunity today and help millions of students around the world.

Ranked #1 Education App

Download in

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Download in

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Knowunity is the #1 education app in five European countries

4.9+

Average app rating

15 M

Pupils love Knowunity

#1

In education app charts in 12 countries

950 K+

Students have uploaded notes

Still not convinced? See what other students are saying...

iOS User

I love this app so much, I also use it daily. I recommend Knowunity to everyone!!! I went from a D to an A with it :D

Philip, iOS User

The app is very simple and well designed. So far I have always found everything I was looking for :D

Lena, iOS user

I love this app ❤️ I actually use it every time I study.