IGCSE 0620 Chemistry Notes
Chemical energetics Notes Part 1
Exothermic and endothermic reactions
1 State that an exothermic reaction transfers thermal energy to the
surroundings leading to an increase in the temperature of the
surroundings.
2 State that an endothermic reaction takes in thermal energy from the
surroundings leading to a decrease in the temperature of the
surroundings.
3 Interpret reaction pathway diagrams showing exothermic and
endothermic reactions.
4 State that the transfer of thermal energy during a reaction is called the
enthalpy change, ∆H, of the reaction. ∆H is negative for exothermic
reactions and positive for endothermic reactions
5 Define activation energy, Ea, as the minimum energy that colliding
particles must have to react
6 Draw and label reaction pathway diagrams for exothermic and
endothermic reactions using information provided, to include:
(a) reactants
(b) products
(c) enthalpy change of the reaction, ∆H
(d) activation energy, Ea
7 State that bond breaking is an endothermic process and bond making is
an exothermic process and explain the enthalpy change of a reaction in
terms of bond breaking and bond making
8 Calculate the enthalpy change of a reaction using
bond energies
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, IGCSE 0620 Chemistry Notes
Chemical energetics
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Chemical energetics Notes Part 1
Exothermic and endothermic reactions
1 State that an exothermic reaction transfers thermal energy to the
surroundings leading to an increase in the temperature of the
surroundings.
2 State that an endothermic reaction takes in thermal energy from the
surroundings leading to a decrease in the temperature of the
surroundings.
3 Interpret reaction pathway diagrams showing exothermic and
endothermic reactions.
4 State that the transfer of thermal energy during a reaction is called the
enthalpy change, ∆H, of the reaction. ∆H is negative for exothermic
reactions and positive for endothermic reactions
5 Define activation energy, Ea, as the minimum energy that colliding
particles must have to react
6 Draw and label reaction pathway diagrams for exothermic and
endothermic reactions using information provided, to include:
(a) reactants
(b) products
(c) enthalpy change of the reaction, ∆H
(d) activation energy, Ea
7 State that bond breaking is an endothermic process and bond making is
an exothermic process and explain the enthalpy change of a reaction in
terms of bond breaking and bond making
8 Calculate the enthalpy change of a reaction using
bond energies
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, IGCSE 0620 Chemistry Notes
Chemical energetics
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