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9 Cards in this Set
- Front
- Back
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Examples of exothermic reactions |
Neutralisation Combustion Oxidation |
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Examples of endothermic reactions |
Thermal decomposition Citric acid + sodium hydrogen carbonate |
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Non rechargeable battery example |
Alkaline battery |
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Words to help with electrolysis |
ANOX - anode oxidation REDCAT - reduction cathode OILRIG - oxidation is loss reduction is gain |
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Breaking bonds ... |
Requires energy (endothermic) |
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Forming bonds ... |
Releases energy (exothermic) |
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Electrochemical cell |
2 electrodes and an electrolyte Electrodes are usually metal as they can conduct electricity The chemical reaction between the electrodes and the electrolyte set up a charge difference If the electrodes are connected by wire, the charge is able to flow and electricity is produced |
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Fuel cells |
Uses oxygen Fuel enters, becomes oxidised and sets up a potential difference Anode: H2 --> 2h+ + 2e- (oxidation) Cathode: O2 + 4h+ + 4e- --> 2H2O Oxygen gains electrons from the cathode and reacts with h+ ions (coming from the electrolyte and previous reaction at anode) reduction Overall: 2h2 + O2 --> 2H2O |
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Fuel cells vs batteries |
Only product is water and heat Electric batteries polluting to get rid of - made of toxic metal compounds Each time recharged decrease how much it holds Batteries more expensive than fuel cells Batteries store less energy |
