Primary galvanic cells and fuel cells as sources of energy Flashcards
Conjugate redox pair
the electron donor (reactant/product) and its corresponding electron acceptor (product/reactant)
Half-equation
reduction or oxidation equation of a complete redox reaction
Overall redox equation
equation of a complete redox reaction combining reduction
and oxidation half-equations
Oxidation
chemical reaction in which a chemical species loses one or more electrons
Oxidation state
number assigned to an atom that can be used to determine the movement of electrons in redox reactions
Oxidised
describes a chemical species that has lost one or more electrons
Oxidising agent
chemical species that oxidises another substance by accepting one or more electrons
Redox reaction
chemical reaction involving the transfer of one or more electrons between chemical species
Reduced
describes a chemical species that has gained one or more electrons
Reducing agent
chemical species that reduces another substance by donating one or more electrons
Reduction
chemical reaction in which a chemical species gains one or more electrons
Acidic environment
solution with a greater concentration of hydrogen ions (H ) than hydroxideions(OH )
Basic environment
solution with a greater concentration of hydroxide ions (OH ) than hydrogenions(H )
Anode
electrode where oxidation (loss of electrons) occurs
Cathode
electrode where reduction (gain of electrons) occurs
Current
a flow of charged particles (ions or electrons)
Electrochemical cell
cell involving conversions between electrical and chemical energy
Electrochemical series
ranking of chemical species in order of their reducing and oxidising strength
Electrode
electrically conductive medium
Electrolyte
solution, liquid, or gel containing ions
External circuit
flow of electrons through an external wire
Feasible reaction
a reaction that could occur but will not necessarily spontaneously react or be observable
Galvanic cell
electrochemical cell in which chemical energy from spontaneous redox reactions is converted into electrical energy
Half-cell
half of a galvanic cell where either oxidation or reduction reactions occur separated from the other half-cell
Internal circuit
flow of ions through a salt bridge
Primary cell
cell that cannot be recharged
Salt bridge
connection that allows the flow of ions between two half-cells to complete the circuit
Cell voltage
voltage produced between the anode and cathode of an electrochemical cell
Standard electrode potential (E 0)
potential of a half-cell reaction, given in volts (V), relative to the Standard Hydrogen Electrode
Standard Hydrogen Electrode (SHE)
standard H+(aq)/H2(g) half-cell with standard electrode potential 0.00 V, which the electrochemical series is created with respect to
Voltage (V)
the potential difference in energy per unit charge between two points
Fuel cell
electrochemical cell that continuously converts chemical energy into electrical energy via a redox reaction
Porous electrode
material with many holes (pores) used in a fuel cell to maximise the ability of gaseous reactants to come into contact with the electrolyte
Coulomb
unit of electric charge (equal to the quantity of charge carried by a current of 1 ampere in 1 second)
Electric charge
property of matter carried by current and measured in coulombs where the charge on a single electron is -1.60 x 10^-19 coulombs
Faraday constant (F)
charge on one mole of charged particles, equal to 96 500 coulombs per mole
Green chemistry
set of principles aimed at reducing the use or production of harmful substances in chemical processes
Feedstock
raw material used for producing another product
Renewable resource
resource capable of being replaced by natural processes within a relatively short period of time
Sustainable
can be produced at a rate that is greater than or equal to the rate of consumption without compromising future generations
Sustainable Development Goals
set of 17 objectives to promote a positive present and future for people and the planet
