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AQA Combined Chemistry Paper 2 Revision Tips PDF | GCSE Chemistry Revision in One Day

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AQA Combined Chemistry Paper 2 Revision Tips PDF | GCSE Chemistry Revision in One Day

Manveer

@manveerssss

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This document covers key topics in GCSE Chemistry, focusing on rates of reaction, reversible reactions, and dynamic equilibrium. It provides essential information for students preparing for their AQA combined chemistry paper 2, offering valuable chemistry revision techniques and insights into factors affecting chemical reactions.

18/06/2023

1090

Reversible Reactions and Dynamic Equilibrium

This page introduces the concept of reversible reactions and dynamic equilibrium in chemistry.

Definition: A reversible reaction is one where the products can react to reform the original reactants.

Key points:

Reversible reactions occur in closed systems where no reactants or products can escape.
These reactions reach a state of dynamic equilibrium when forward and backward reactions occur at the same rate.
The position of equilibrium depends on temperature, pressure, and concentration.

Example: The reaction between hydrated copper sulfate and anhydrous copper sulfate is reversible.

Le Chatelier's Principle is introduced, which states that if conditions of a reversible reaction are changed, the system will try to counteract the change.

Highlight: Understanding reversible reactions and equilibrium is crucial for GCSE Chemistry past papers and exams.

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Concentration and Rate of Reaction: Disappearing Cross Practical

This page outlines another practical method to investigate the effect of concentration on reaction rate.

Procedure:

Add 50cm³ of sodium thiosulfate to a conical flask placed on a printed black cross.
Add 5cm³ of 1.0M hydrochloric acid.
Start a stopwatch and observe the solution becoming cloudy.
Stop the stopwatch when the cross is no longer visible.

Highlight: This experiment is an excellent way to visually demonstrate how concentration affects the rate of reaction in chemistry.

Vocabulary: The cloudiness is caused by the production of sulfur in the reaction.

View

Rate of Reaction and Collision Theory

This page discusses the factors affecting the rate of chemical reactions, emphasizing the importance of collision theory.

Definition: Collision theory states that for a reaction to occur, particles must collide with sufficient energy and correct orientation.

Factors influencing reaction rates include:

Pressure of reacting gases
Concentration of reactants
Temperature
Surface area of reactants
Catalysts

Highlight: Increasing temperature, concentration, pressure, or surface area generally increases the rate of reaction by promoting more frequent and energetic collisions.

The rate of reaction can be measured by the slope of a graph showing the quantity of reactant used or product formed over time.

Vocabulary: Activation energy is the minimum energy required for a successful collision between reactant particles.

Example: Powdering a solid reactant increases its surface area, leading to a higher rate of reaction.

View

Determining Purity of Substances

This page discusses methods for determining the purity of substances using melting and boiling points.

Key points:

Pure substances have specific melting and boiling points.
Impurities lower the melting point and raise the boiling point of a substance.
Comparing observed melting/boiling points with known values can indicate purity.

Highlight: Understanding how to determine substance purity is crucial for GCSE Chemistry revision.

Example: If a sample boils over a range of temperatures rather than at a specific point, it likely contains impurities.

View

Hydrocarbons and Crude Oil

This page covers hydrocarbons, their properties, and processes related to crude oil.

Key points:

Hydrocarbons are compounds containing only carbon and hydrogen.
Properties like boiling point and viscosity depend on the size and structure of hydrocarbon molecules.
Cracking is a process used to break down long-chain hydrocarbons into shorter, more useful molecules.

Definition: Fractional distillation is a method used to separate crude oil into fractions based on boiling points.

Example: Steam cracking and catalytic cracking are two methods used to produce shorter chain hydrocarbons and alkenes.

Highlight: Understanding hydrocarbon chemistry is essential for AQA GCSE Chemistry revision.

View

Testing for Gases

This page provides methods for identifying common gases in chemistry experiments.

Gas tests:

Carbon dioxide: Bubbles through limewater, turning it cloudy.
Hydrogen: Burns with a 'pop' sound when a lit splint is held near it.
Oxygen: Relights a glowing splint.
Chlorine: Bleaches damp litmus paper white.

Highlight: These gas tests are frequently featured in GCSE Chemistry past papers and practical exams.

Example: To test for carbon dioxide, bubble the gas through limewater. If it turns cloudy, carbon dioxide is present.

View

Concentration and Rate of Reaction: Gas Volume Measurement

This page describes an experimental method to measure the rate of reaction by monitoring gas volume.

Procedure:

Add 50cm³ of 1.0M sulfuric acid to a conical flask.
Add 3cm magnesium ribbon to the flask.
Seal with a bung attached to a gas syringe.
Record gas volume every 10 seconds.

Highlight: This experiment demonstrates how concentration affects the rate of reaction, a key topic in GCSE Chemistry.

Example: Repeating the experiment with different acid concentrations shows how concentration influences reaction rate.

View

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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.

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Knowunity is the #1 education app in five European countries

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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.

Can't find what you're looking for? Explore other subjects.

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.

Download in

Google Play

Download in

App Store

4.9+

Average app rating

13 M

Pupils love Knowunity

#1

In education app charts in 11 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.

Subjects

Chemistry

The earth & atmosphere

Atmospheric pollution

AQA Combined Chemistry Paper 2 Revision Tips PDF | GCSE Chemistry Revision in One Day

View

Manveer

@manveerssss

1 Follower

AQA Combined Chemistry Paper 2 Revision Tips PDF | GCSE Chemistry Revision in One Day

18/06/2023

1090

Reversible Reactions and Dynamic Equilibrium

This page introduces the concept of reversible reactions and dynamic equilibrium in chemistry.

Definition: A reversible reaction is one where the products can react to reform the original reactants.

Key points:

Reversible reactions occur in closed systems where no reactants or products can escape.
These reactions reach a state of dynamic equilibrium when forward and backward reactions occur at the same rate.
The position of equilibrium depends on temperature, pressure, and concentration.

Example: The reaction between hydrated copper sulfate and anhydrous copper sulfate is reversible.

Le Chatelier's Principle is introduced, which states that if conditions of a reversible reaction are changed, the system will try to counteract the change.

Highlight: Understanding reversible reactions and equilibrium is crucial for GCSE Chemistry past papers and exams.

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Join milions of students

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Concentration and Rate of Reaction: Disappearing Cross Practical

This page outlines another practical method to investigate the effect of concentration on reaction rate.

Procedure:

Add 50cm³ of sodium thiosulfate to a conical flask placed on a printed black cross.
Add 5cm³ of 1.0M hydrochloric acid.
Start a stopwatch and observe the solution becoming cloudy.
Stop the stopwatch when the cross is no longer visible.

Highlight: This experiment is an excellent way to visually demonstrate how concentration affects the rate of reaction in chemistry.

Vocabulary: The cloudiness is caused by the production of sulfur in the reaction.

Sign up to get unlimited access to thousands of study materials. It's free!

Access to all documents

Join milions of students

Improve your grades

By signing up you accept Terms of Service and Privacy Policy

Rate of Reaction and Collision Theory

This page discusses the factors affecting the rate of chemical reactions, emphasizing the importance of collision theory.

Definition: Collision theory states that for a reaction to occur, particles must collide with sufficient energy and correct orientation.

Factors influencing reaction rates include:

Pressure of reacting gases
Concentration of reactants
Temperature
Surface area of reactants
Catalysts

Highlight: Increasing temperature, concentration, pressure, or surface area generally increases the rate of reaction by promoting more frequent and energetic collisions.

The rate of reaction can be measured by the slope of a graph showing the quantity of reactant used or product formed over time.

Vocabulary: Activation energy is the minimum energy required for a successful collision between reactant particles.

Example: Powdering a solid reactant increases its surface area, leading to a higher rate of reaction.

Sign up to get unlimited access to thousands of study materials. It's free!

Access to all documents

Join milions of students

Improve your grades

By signing up you accept Terms of Service and Privacy Policy

Determining Purity of Substances

This page discusses methods for determining the purity of substances using melting and boiling points.

Key points:

Pure substances have specific melting and boiling points.
Impurities lower the melting point and raise the boiling point of a substance.
Comparing observed melting/boiling points with known values can indicate purity.

Highlight: Understanding how to determine substance purity is crucial for GCSE Chemistry revision.

Example: If a sample boils over a range of temperatures rather than at a specific point, it likely contains impurities.

Sign up to get unlimited access to thousands of study materials. It's free!

Access to all documents

Join milions of students

Improve your grades

By signing up you accept Terms of Service and Privacy Policy

Hydrocarbons and Crude Oil

This page covers hydrocarbons, their properties, and processes related to crude oil.

Key points:

Hydrocarbons are compounds containing only carbon and hydrogen.
Properties like boiling point and viscosity depend on the size and structure of hydrocarbon molecules.
Cracking is a process used to break down long-chain hydrocarbons into shorter, more useful molecules.

Definition: Fractional distillation is a method used to separate crude oil into fractions based on boiling points.

Example: Steam cracking and catalytic cracking are two methods used to produce shorter chain hydrocarbons and alkenes.

Highlight: Understanding hydrocarbon chemistry is essential for AQA GCSE Chemistry revision.

Sign up to get unlimited access to thousands of study materials. It's free!

Access to all documents

Join milions of students

Improve your grades

By signing up you accept Terms of Service and Privacy Policy

Testing for Gases

This page provides methods for identifying common gases in chemistry experiments.

Gas tests:

Carbon dioxide: Bubbles through limewater, turning it cloudy.
Hydrogen: Burns with a 'pop' sound when a lit splint is held near it.
Oxygen: Relights a glowing splint.
Chlorine: Bleaches damp litmus paper white.

Highlight: These gas tests are frequently featured in GCSE Chemistry past papers and practical exams.

Example: To test for carbon dioxide, bubble the gas through limewater. If it turns cloudy, carbon dioxide is present.

Sign up to get unlimited access to thousands of study materials. It's free!

Access to all documents

Join milions of students

Improve your grades

By signing up you accept Terms of Service and Privacy Policy

Concentration and Rate of Reaction: Gas Volume Measurement

This page describes an experimental method to measure the rate of reaction by monitoring gas volume.

Procedure:

Add 50cm³ of 1.0M sulfuric acid to a conical flask.
Add 3cm magnesium ribbon to the flask.
Seal with a bung attached to a gas syringe.
Record gas volume every 10 seconds.

Highlight: This experiment demonstrates how concentration affects the rate of reaction, a key topic in GCSE Chemistry.

Example: Repeating the experiment with different acid concentrations shows how concentration influences reaction rate.

Can't find what you're looking for? Explore other subjects.

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.

Download in

Google Play

Download in

App Store

4.9+

Average app rating

13 M

Pupils love Knowunity

#1

In education app charts in 11 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