C5 ENERGY CHANGES
No description yet. This curated deck is ready for daily study.
Card preview (11)
conservation of energy principle?
we can’t ‘lose’ or ‘gain’ energy: Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed.
exothermic reaction?
energy is transferred to the surroundings (temp increases)
endothermic reaction?
energy is taken in from the surroundings (temp decreases)
activation energy?
minimum amount of energy that particle needs to react
reaction profile?
graph shows the relative energies of reactants and product as well as activation energy of the reaction.
cell?
composed of two electrodes dipped in electrolyte solution, it produces electricity from a chemical reaction
battery?
two or more cells connected in series.
what determines the voltage obtained from a cell?
identities of metals used as electrodes and the identity and concentration of an electrolyte
what determines the voltage obtained from a cell?
identities of metals used as electrodes and the identity and concentration of an electrolyte
advantages / disadvantages of using cells and batteries?
(+) more cheap , less cheap , some are rechargeable , a convenient source of electrical energy. (-) harmful chemicals
describe rechargeable and non-rechargeable cells?
rechargeable - chemical reactions are reversed when an external current is supplied non-rechargeable - reactants are used up cannot be recharged.