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Notes and Questions: Aqa Gcse

The document discusses energy changes that occur during chemical reactions. It defines exothermic reactions as those where energy is transferred to the surroundings, meaning the products have less energy than the reactants. Endothermic reactions are defined as those where energy is taken in from the surroundings, so the products have more energy than the reactants. It also discusses reaction profiles and how they can show the relative energies of reactants and products, as well as the activation energy and overall energy change. Bond breaking requires energy while bond formation releases energy.

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237 views12 pages

Notes and Questions: Aqa Gcse

The document discusses energy changes that occur during chemical reactions. It defines exothermic reactions as those where energy is transferred to the surroundings, meaning the products have less energy than the reactants. Endothermic reactions are defined as those where energy is taken in from the surroundings, so the products have more energy than the reactants. It also discusses reaction profiles and how they can show the relative energies of reactants and products, as well as the activation energy and overall energy change. Bond breaking requires energy while bond formation releases energy.

Uploaded by

api-422428700
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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AQA GCSE

Notes and Questions

Energy Changes
Energy transfer:

Energy is c___________ in chemical reactions. The amount of

e______ in the u________ at the end of a chemical reaction is the

same as b_________. If a reaction t_________ energy to the

surroundings the p__________ molecules must have l____ e_____

than the r_________, by the amount transferred.

1. Draw the two different energy diagrams:

2. Define an exothermic reaction:

3. Define an endothermic reaction:


4. Identify the following as either exothermic or endothermic
reactions. How did you decide?
5. Draw how you might practically assess whether or not a
reaction is exothermic or endothermic?
Reaction Profiles:

Chemical reactions can only occur when r_________ particles


c________ with each other and with s___________ e_______.

6. Define the Activation Energy?

Reaction profiles can be used to show the relative energies of the


reactants and products, the activation energy and the overall energy
change.

7. Draw the two different types of reaction profile?


The energy change of reactions:

During a chemical reaction:


 energy must be supplied to b______ b______s in the
reactants.
 energy is released when b_____ in the products are
f________.

8. Explain an endothermic reaction in terms of bond changes?

9. Explain an exothermic reaction in terms of bond changes?


10. How do you calculate the energy released during a reaction?
11. Calculate the energy in the following reaction?
12. Calculate the energy in the following reaction?
13. Calculate the energy in the following reaction?

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