Chemistry Final - Unit 9 (Redox Reactions & Electrochemistry)

oxidation and reduction must occur _____

simultaneously

the total increase in oxidation numbers of the oxidized substance must equal the _______

decrease in oxidation numbers of the reduced substance

what is a free element?

an element in an redox reaction that is standing alone with a charge of 0

what is electrochemistry?

the study of the interchange of chemical and electrical energy

redox reactions also involve a transfer of _____

electrons

what did Michael Faraday discover?

that the water solutions called electrolytes conduct electricity

what is an electrolyte?

any substance which dissolved in water to form a solution that will conduct an electric current

what are solutions that cannot conduct electricity called?

non-electrolytes

solutions in which the solute is present entirely as ions are called ______

strong electrolytes

a solution in which there is a low concentration of dissolved ions is called a ____

weak electrolyte

dissociation is the separation of ions when an ____ compound dissolves

ionic

ionization is when a ______ substance dissolves into ions

covalent/molecular

water molecules pull ions apart due to its strong ______

covalent bonds

voltaic (galvanic) cells are _____

spontaneous

electrolytic cells are _____

non-spontaneous

what are electrochemical cells?

a system of electrodes and electrolytes where redox reactions occur

The E°_cell of a voltaic/galvanic cell is ____

positive

The E°_cell of an electrolytic cell is ____

negative

what is an electrode?

an electrical conductor (metal strip) used to establish contact with the electrolyte

what is an electrolyte?

a liquid, paste, or gel that serves to conduct charge bu moving ions in the cell

oxidation occurs at the ____

anode

reduction occurs at the ____

cathode

what is a half cell?

a single electrode immersed in a solution of its ions

what is a salt bridge?

a device placed between cells that maintains neutrality by allowing ions to migrate between cells

a salt bridge is used in _____

galvanic cells

what is an external circuit?

the part of the cell where charge is conducted as current of moving electrons

what is Standard Electrode Reduction Potential (E°)?

the measurement, in volts, of the tendency for a half reaction to occur as reduction

what is cell potential?

the measure of the diriving force, in volts, for an electrochemical reaction

in a voltaic/galvanic cell, the ____ is the negative electrode

anode

what is an example of a voltaic cell?

batteries

electrons flow from _____ to ____

anode to cathode

in an electrolytic cell, the anode is the ____ electrode

positive

equation for E°_cell:

E°_cathode - E°_anode

examples of electrolytic cells:

electrolysis, electroplating