Chemistry Chapter 12: Electrochemistry (4 Stars) Flashcards
A __________ cell describes any cell in which oxidation–reduction reactions take place. Certain characteristics are shared between all types of electrochemical cells.
electrochemical
______ are strips of metal or other conductive materials placed in an electrolyte solution.
Electrodes
The _____ is always the site of oxidation. It attracts anions.
anode
The cathode is always the site of ______. It attracts cations.
reduction
Electrons flow from the _____ to the _______
anode to the cathode.
______ flows from the cathode to the anode.
Current
Cell diagrams are shorthand notation that represent the reactions taking place in _______
electrochemical cell.
Cell diagrams are written from _____ to ______with electrolytes (the solution) in between.
anode to cathode
A vertical line represents a _____boundary, and a double vertical line represents a salt bridge or other physical boundary.
phase
Galvanic (voltaic) cells house spontaneous reactions (ΔG < 0) with a _____ electromotive force.
positive
Electrolytic cells houses ______ reactions (ΔG > 0) with a negative electromotive force. These nonspontaneous cells can be used to create useful products through electrolysis.
nonspontaneous
______ cells are a specialized form of a galvanic cell in which both electrodes are made of the same material.
Concentration
Rather than a potential difference causing the movement of charge, it is the concentration gradient between the two solutions.
The charge on an electrode is _____ on the type of electrochemical cell one is studying.
dependent
For galvanic cells, the anode is ______ charged and the cathode is ______ charged.
negatively charged
positively charged.
For electrolytic cells, the ____ is positively charged and the _____ is negatively charged.
anode
cathode
_________ are electrochemical cells that can experience charging (electrolytic) and discharging (galvanic) states.
Rechargeable batteries
Rechargeable batteries are often ranked by energy density—the amount of energy a cell can produce relative to the mass of battery material.
______ is an above-average current transiently released at the beginning of the discharge phase; it wanes rapidly until a stable current is achieved. Cell Potentials
Surge current
A reduction potential quantifies the tendency for a species to gain electrons and be reduced. The higher the reduction potential, the more a given species wants to be ______.
reduced.
Standard reduction potentials (E° red) are calculated by comparison to the standard ______ electrode (SHE) under the standard conditions of 298 K, 1 atm pressure, and 1 M concentrations.
hydrogen
The standard hydrogen electrode has a standard reduction potential of ___ V.
0 V.
Standard electromotive force (E° cell) is the difference in standard reduction potential between the ______
two half-cells.
For galvanic cells, the difference of the reduction potentials of the two half reactions is ______; for electrolytic cells, the difference of the reduction potentials of the two half-reactions is negative.
positive
_______ force and change in free energy always have opposite signs.
Electromotive
When Ecell is positive, ΔG° is _____. This is the case in galvanic cells.
negative
When Ecell is ______, ΔG° is positive. This is the case in electrolytic cells.
negative
When Ecell is 0, ΔG° is _____. This is the case in concentration cells.
0
The _______ describes the relationship between the concentration of species in a solution under nonstandard conditions and the electromotive force.
Nernst equation
When Keq (the ratio of products’ concentrations at equilibrium over reactants’, raised to their stoichiometric coefficients) is greater than 1, Ecell is _____
positive.
When Keq is less than 1, Ecell is _____
negative.
When Keq is equal to 1, Ecell is ___
0.
