Chemical reactions and energy Flashcards
what is an exothermic reaction
when energy is transferred to the surroundings
what happens during an exothermic reaction
the temperature of the surroundings increases
what reactions are exothermic
combustion, neutralisation and oxidation
uses of exothermic reactions
self-heating food cans and outdoor hand warmers
endothermic reaction
energy is taken from its surroundings
what happens during an endothermic reaction
the temperature of the surroundings decreases
examples of endohermic reactions
thermal decompostition and electrolysis
endothermic reactions uses
instant ice packs for injuries
what does a energy level diagram show
whether a reaction is exothermic or endothermic
what does a energy profile show in a exothermic reaction
- products are lower than reactants
- downwards arrow shows that energy is given out
what does a energy profile show in an endothermic reaction
- products are higher than reactants
- upwards arrow shows that energy is being taken in
what does a reaction profile show
- how much energy of the chemicals changes during a reaction
- activation energy which is the minimum energy needed to start a reation
what is the overall change in energy in a reaction
difference between the energy of the reactants and the energy of the products
what happens during a chemical reaction
- energy is needed to break bonds in the reaction
- energy is released when the bonds in the products are formed
- the difference between the energy needed to break bonds and the energy released when forming bonds determines the type of reaction
