Term
| what are the components of a typical electrochemical cell? |
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Definition
electrodes
electrolyte
outer circuit |
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Term
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Definition
| uses electricity to split a chemical compound |
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Term
| the reduction reaction always tales place at the __ |
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Definition
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Term
| the oxidation reaction always takes place at the __ |
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Definition
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Term
| mnemonic for remembering where half reactions take place |
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Definition
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Term
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Definition
| combines a chemical compound and produces electricity |
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Term
| for an electrolytic cell, tell which electrode is positive and which is negative |
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Definition
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Term
| for a galvanic cell, tell which electrode is positive and which is negative |
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Definition
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Term
| between electrolytic cells and galvanic cells, the cathode-anode polarity is the same or reversed? |
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Definition
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Term
| Faraday's law of electrolysis states... |
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Definition
| that the amount of substance produced/consumed in an electrochemical cell is proportional to the charge passed through the cell |
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Term
| what is the physical meaning of Faraday's constant? |
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Definition
| tells the amount of electric charge carried by 1 mol of charged species |
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Term
| is the electrical resistivity of pure water low or high? why? |
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Definition
very high
because of the low concentration of ions in pure water |
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Term
| what is the volume of H2 produced vs. the volume of O2 produced in an electrolyzer? why? |
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Definition
twice as much H2 is produced as O2
because there is twice as much H than O in water |
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Term
| why is a strong base usually added to the solution of pure water for water electrolysis? |
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Definition
to decrease the resistivity of pure water
also, a strong base is less corrosive to the equipment than a strong acid |
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Term
| the amount of charge passed through an electrolyzer can be found by... |
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Definition
| measuring the amount of gas produced |
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Term
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Definition
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Term
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Definition
1. the sum of the currents into a node equals the sum of the currents out of a node
2. the sum of voltage around a closed loop is zero |
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Term
| what is the purpose of the salt bridge in the Daniell cell? |
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Definition
| to allow the flow of electrons between the electrodes while keeping the electrolyte solutions separate |
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Term
| what is the sign of the potential difference between the cathode and anode for a galvanic cell, EGC? |
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Definition
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Term
| is the potential difference between the cathode and anode for a galvanic cell, EGC, greater than or less than E at equilibrium? |
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Definition
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Term
| what contributes to the internal resistance? |
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Definition
R of the two electrolyte solutions
R of the salt bridge
R of the interfaces between the metal electrodes |
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Term
| what is the sign of the potential difference between the cathode and anode for an electrolytic cell, EEC? |
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Definition
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Term
| is the potential difference between the cathode and anode for an electrolytic cell, EEC, greater than or less than E at equilibrium? |
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Definition
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Term
| define decomposition potential, ED |
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Definition
| minimum theoretical potential at which electrolysis takes place |
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Term
| how is the decomposition potential, ED, related to the equilibrium potential, Eeq? |
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Definition
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Term
| is the equilibrium potential positive or negative for a galvanic cell? |
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Definition
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Term
| is the equilibrium potential positive or negative for an electrolytic cell? |
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Definition
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Term
| what is the sign convention for equilibrium potential with respect to a spontaneous process? |
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Definition
spontaneous: +
nonspontaneous: -
(opposite of ΔG) |
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Term
| between electrolytic mode and galvanic mode for the Daniell cell, is the polarity of cathode and anode the same or reversed? |
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Definition
the same, but they switch sides so that:
Cu electrode is always +
Zn electrode is always - |
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Term
| is it appropriate to use the terms "cathode" and "anode" for a Daniell cell? |
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Definition
no
use "+ electrode" and "- electrode" instead |
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Term
| an equilibrium cell is a cell where... |
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Definition
| electricity is neither consumed nor produced |
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