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14 Cards in this Set
- Front
- Back
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How can you recharge a rechargeable battery? |
Reverse reactions; supply current; force electrons to go in opposite direction around circuit |
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How can you decide if a metal is more reactiv eby electrode potentials? |
Electrode potential is more negative, metal is more reactive |
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What are non-rechargeable cells useful for and what kind of reaction occurs in them? |
Low power/useful for short period of time irreversible |
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What kind of reaction needs to occur in a rechargeable cell? |
Reversible reaction products don't escape/reagents not used up products are insoluble and remain attached to the electrodes |
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Why can't you reacharge a zinc battery? |
Electrode forms casing , so that would deteriorate |
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In general why can't you recharge a normal battery/ |
Would leak or explode/products escape |
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What is an electrolyte? |
Substance that has free ions and can conduct electricity |
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What are the pros of non-rechargeable batteries? |
Cheaper to buy; last longer before running out of charge; less likely to contain toxic materials/heavy metals that are dangerous in landfill/cause pollution |
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What are the pros of rechargeable batteries? |
Cheaper in the long-term provide more power less waste in landifll as less need to be produced less natural resources used |
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What is really important for rechargeable cell? |
Products must be insoluble and remain attached to the electrodes/don't escape so reaction can be reversed when current is supplied |
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What are the pros of fuel cells? |
Don't need recharging only waste is water/no toxic metals/no CO2 |
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What are the cons of fuel cells? |
Need constant supply of oxygen and hydrogen hydrogen produced by electrolysis which releases co2 hydrogen is flammable |
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Describe acidic fuel cell? |
phosphoric acid electrolyte ion exchange membrane between electrodes to allow movement of ions but not electrons porous electrodes containing platinum negative electrode is hydrogen: H2 ----> 2H+ + 2e- Positive is oxygen O2 + 4H+ + 4e- -----> 2H2O |
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Describe alkaline fuel cell |
KOH electrolyte Negative: 2H2 + 4OH- ----> 4H2O + 4e- Positive: O2 + 4e- + 2H2O ----> 4OH- |
