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26 Cards in this Set
- Front
- Back
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What type of cell is a fuel cell?
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an electrochemical cell
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What reaction occurs in a fuel cell?
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hydrogen w/ oxygen (combustion) w/ electrolyte to make water & electricity
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Example of a place where fuel cell is used?
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Space craft.
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What is the charge of each electrode?
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anode is negative, cathode is positive
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What is the reaction at the anode of a fuel cell?
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H2 + 2OH- --> 2H2O + 2e
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What is the reaction at the cathode of a fuel cell?
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O2 + 2H2O + 4e --> 4OH-
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What can an acidic solution replace?
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the alkaline electrolyte (usually phosphoric acid)
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What is the big difference between fuel cells and batteries?
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fuel cells' materials come from external sources and are depleted/used up
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What is an advantage of a fuel cell?
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hydrogen-oxygen fuel cells don't pollute, they only create water + electricity + heat
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What are two disadvantages of fuel cells?
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firstly, the pollution that results from cracking to obtain hydrogen, and secondly, the use of catalysts
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What makes a battery rechargeable?
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the redox rxns are reversible
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What are the types of rechargeable batteries?
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nickel cadium, lithium ion, lead-acid
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What are the details of a lead-acid battery?
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12 volts, 6 2V parts, used in car batteries. anode: Pb cathode: PbO2 electrolyte: H2SO4
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Reaction at anode of lead acid battery? (oxidation)
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Pb + SO4(2-) --> PbSO4 + 2e
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Reaction at cathode of lead acid battery? (reduction)
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PbO2 + 4H(+) + SO4(2-) + 2e --> PbSO4 + 2H2O
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What are the details of a nickel cadmium battery?
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1.2V, used in toys. anode: Cd, cathode: Ni3+O(OH), electrolyte: KOH
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Reaction at anode of NiCd battery? (oxidation)
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Cd + 2OH(-) --> Cd(OH)2 + 2e
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Reaction at cathode of NiCd battery? (reduction)
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NiO(OH)3+ + e + H2O --> Ni(OH)2(2+) + OH-
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What are the details of a lithium ion battery?
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3-4V, used in phones/laptops. anode: LixC6, cathode: CoO2 (or MnO2), electrolyte: LiPF6
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Reaction at anode of lithium ion battery? (oxidation)
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LixC6 --> xLi(+) + 6C + e-
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Reaction at cathode of lithium ion battery? (reduction)
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CoO2 + xLi(+) + e --> Lix6O2
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What is a disadvantage of a lead-acid battery?
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lead and H2SO4 is polluting
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What is a disadvantage of a nickel cadmium battery?
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expensive to produce and hazardous to dispose of
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What is a disadvantage of a lead-acid battery?
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short lifespan
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3 similarities between fuel cells and rechargeable batteries?
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a) both generate electrical energy from chemical energy
b) both require anode/cathode/electrolyte c) current made based on separation of rxns |
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3 difference between fuel cells and rechargeable batteries?
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a) fuel cells require external source, batteries don't.
b) fuel cells are bigger than batteries c) batteries are cheaper than fuel cells |
