IGCSE 0620 Chemistry Notes
Chemical energetics Notes Part 2
Exothermic Vs Endothermic reactions
Exothermic reaction Endothermic reaction
Energy is lost from the system Energy is gained from the
to the surroundings surroundings by the system
Temperature of the surroundings, Temperature of the surroundings,
reaction mixture , solution increases reaction mixture , solution decreases
(become hotter) (become colder)
reactants →products + energy reactants + energy →product
Δ H is Negative Δ H is Positive
If the energy lost is greater than the If the energy taken in is greater than
energy taken in the energy lost
products have less energy than the products have more energy than
reactants reactants
Energy needed to break the bonds in Energy needed to break the bonds in
reactants is less than the energy reactants is greater than the energy
released in making new bonds in the released in making new bonds in the
products products
Examples of exothermic reactions: Examples of endothermic reactions:
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Chemical energetics Notes Part 2
Exothermic Vs Endothermic reactions
Exothermic reaction Endothermic reaction
Energy is lost from the system Energy is gained from the
to the surroundings surroundings by the system
Temperature of the surroundings, Temperature of the surroundings,
reaction mixture , solution increases reaction mixture , solution decreases
(become hotter) (become colder)
reactants →products + energy reactants + energy →product
Δ H is Negative Δ H is Positive
If the energy lost is greater than the If the energy taken in is greater than
energy taken in the energy lost
products have less energy than the products have more energy than
reactants reactants
Energy needed to break the bonds in Energy needed to break the bonds in
reactants is less than the energy reactants is greater than the energy
released in making new bonds in the released in making new bonds in the
products products
Examples of exothermic reactions: Examples of endothermic reactions:
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