Electrochemistry Flashcards
Electrochemical reactions include ___ reactions that __ electrical energy and ___ reactions that ___ electrical energy to produce a ___ change. Both types of reactions always involve a transfer of ___ through the processes of ___ and ____. Like other chemical reactions, they result in conservation of charge and ___
spontaneous, produce, nonspontaneous, use, chemical, electrons, oxidation, reduction, mass
Electrochemical cells are __ ___ in which a redox reaction occurs, either to provide __ __ or to use electrical energy for a useful purpose.
contained systems, electrical energy
spontaneous reactions occur in ____ ___, and nonspontaneous reactions occur in ___ ___. Both types contain electrical conductors known as ____, where oxidation and reduction occur. The electrode where oxidation occurs is called the ___, and the electrode where reduction occurs is called the ____.
galvanic cells, electrolytic cells, electrodes, anode, cathode
A redox reaction occurring in a galvanic cell has a ____ delta G. Galvanic cell reactions ___ energy and are used to do ___. The energy is harnessed by placing the oxidation and reduction half reactions in separate containers called ___. These are then connected by an apparatus that allows the flow of ____ between the half-cells, creating a ____.
negative, supply, work, half-cells, electrons, circuits
Because of the flow of electrons ___ from the anode and ___ the cathode, __ ___ can begin to build up in the solution surrounding the cathode, and ___ ___ can begin to build up in the solution surrounding the anode. If enough charge were to build up, the reaction would become ___ and cease. However, this charge gradient can be dissipated by a _____ ___ which permits the exchange of cations and anions. This structure contains an __ __, usually __ or ___, whose ions will not react direct with the electrodes or the ions in solution
away, toward, negative charge, positive charge, unfavorable, salt bridge, inert electrolyte, KCl, NH4NO3
The ___ from the salt bridge flow to the cathode, and the ___ flow to the anode. This flow eventually __- the salt bridge, and along with the finite quantity of ___, the cell is relatively short lived
cations, anions, depletes, ions
In a cell diagram, the reactants and products are always listen from left to right in the form ___ |__ __||___ _____ | _____. A single vertical line indicates a __ __, and a double vertical line indicates the presence of a salt bridge, or some other type of ___.
anode, anode solution, cathode solution, cathode, phase boundary, barrier
A redox reaction occurring in an electrolytic cell has a ___ delta G and is therefore nonspontaneous. In ____, electrical energy is required to induce reaction. The oxidation and reduction half reactions are placed in the __ ___ and no ___ __ is required. A ___ or __ __ is used to drive the reaction
positive, electrolysis, same container, salt bridge, battery, power source
The cations in solution migrate towards the ___ where they are ___, while the ___ migrate towards the ____, where they are ____. The electrons liberated at the _____ travel through the ___ to provide the electrons used at the ___.
cathode, reduced, anions, oxidized, anode, cathode
Electrolytic cells are used in ___ as the major source of __ and ___ production. The latter is a ___ at the temperature of molten NaCl and is less ___ than the molten ___, meaning it is easily ____ as it floats to the top of the reaction vessel
industry, sodium, chlorine, liquid, dense, salt, removed
The anode of an electrolytic cell is considered ____, because it is attached to the positive pole of the battery. The anode of a galvanic cell is considered ___ because the spontaneous ____ reaction that takes place there is the original source of the cell’s _____ (negative charge). However, oxidation always takes place at the _____ and electrons always flow from anode to cathode.
positive, negative, oxidation, electrons, anode
In ____, a technique often used to separate amino acids based on their ___ points, the positively charged amino acid cations will migrate towards the ___, while the negatively charged amino acid ___, migrate towards the ___.
electrophoresis, isoelectric, cathode, anode
Equation to determine how many moles of electrons are transferred by an electrochemical cell
current (time) = (moles of electrons) (Faraday)
The tendency of a species to acquired electrons
Reduction potential
the more ___ the reduction potential, the greater the tendency to be ___. The reduction potential is defined relative to the __ __ ___, which is arbitrarily given a potential of ____ volts. standard reduction potential is measured at _____°C, a ____ concentration for each ion participating in the reaction, a partial pressure of ___ for each gas that is present, and metals in their __ ___. When two half reactions are occurring, the half reaction with the ___ reduction potential will occur in reverse as an ____.
positive, reduced, standard hydrogen electrode, 0, 25, 1, 1atm, pure state, lower, oxidation
