Temperature Changes Flashcards
(14 cards)
Exothermic >
When temperature increases, energy is transferred from the reaction to the surroundings.
Endothermic >
When temperature decreases, energy is transferred from the surroundings to the reaction.
E (energy transferred) =
mc∆T (mass x SHC x change in temp.) (J)
SHC measured in:
J/kg(g)ºC
Uses of exothermic reactions
> Combustion
Heat packs
self-heating cans
Uses of endothermic reactions
> Icepacks
> Photosynthesis
Activation energy >
Minimum energy required for a reaction to occur
Overall energy change (reaction energy diagram)
∆H
Activation energy (letter symbol)
Ea
Exothermic: products vs. reactants (energy)
reactants > products
Endothermic: products vs. reactants (energy)
products > reactants
Catalyst >
A substance that speeds up a reaction without being used up itself
Catalysts’ effects on activation energy
They lower it
A reaction is
the making and/or breaking of chemical bonds
