ELECTROCHEMISTRY NEW EXAM STUDY SET WITH
100% VERIFIED SOLUTIONS!!
Electrochemistry - ANSWER>>Electrochemistry is the study of chemical processes that
cause electrons to move. This movement of electrons is called electricity, which can be
generated by movements of electrons from one element to another in a reaction known
as an oxidation-reduction ("redox") reaction
Galvanic (voltaic) cells - ANSWER>>which are thermodynamically favorable chemical
reactions (battery)
Electrolytic cells - ANSWER>>which are thermodynamically unfavorable and require
external e− source (a direct current or DC power source)
balancing redox reactions in an acidic solution - ANSWER>>add h20 to balance O and
H+ to balance the h atoms
balancing redox reactions in an basic solution - ANSWER>>do everything like the acidic
one except at the end for each H+ add an OH- to BOTH SIDES!!!
and combined H+ and OH-to make H2O
and subtract from both sides if possible
the experimental apparatus for generating electricity through the use of a spontaneous
reaction is called a - ANSWER>>galvanic cell or voltaic cell
anode - ANSWER>>anode in a galvanic cell is the electrode at which oxidation occurs
and the cathode is the electrode at which reduction occurs.
oxidation - losing electrons
,the cathode - ANSWER>>the cathode is the electrode at which reduction occurs.
reduction gaining electrons
Salt bridge - ANSWER>>used to maintain electrical neutrality in a galvanic cell; may be
filled with agar which contains a neutral salt
Electron flow - ANSWER>>ALWAYS through the wire from anode to cathode
(alphabetical order)
Voltmeter - ANSWER>>measures the cell potential (emf) in volts.
Inert electrodes - ANSWER>> used when a gas is involved OR ion to ion involved such as
Fe3+ being reduced to Fe2+ rather than Fe0; made of Pt (expensive) or graphite(cheap)
oxidation occurs at the anode (may show mass decrease) - ANSWER>>
which one anode or cathode have mass decreases - ANSWER>> anode
Salt Bridge - ANSWER>>bridge between cells whose purpose is to provide ions to
balance the charge. Usually made of a salt filled agar KNO3) or a porous disk may be
present instead.
EPA - in an electrolytic cell there is a positive anode.
which is more reactive zinc or copper - ANSWER>>Zinc reacts with a solution
containing copper ions. The zinc metal is more reactive than copper metal and so it can
force the copper metal ions to accept electrons and become metal atoms. The zinc
metal passes its electrons to the copper ions.
let say you have copper sulfate in solution which gives Cu⁺² and SO₄⁻²
, before reaction is blue color then with zinc what will the color look like? - ANSWER>>the
zinc since it more reactive than copper will force its electrons on it thus copper will be
natural
and ZnSO₄²⁻ will form
copper will become the ppt
before reaction is blue color then with zinc what will the color look like
colorless
the zinc was being oxide and copper was being reduce
Has does the salt bridge work with the zinc and copper example
Remember copper becomes Cu cause it gains the two electrons from zinc who's is more
reactive than copper - ANSWER>>you will have two buckets one with copper and other
will zinc (in individual buckets)
the zinc electron go through the wire and make the copper neutral the salt brige comes
in made of example Na₂SO₄⁻²
so the SO₄⁻² reacts with the Zn²⁺
sodium might go in the copper to neutral the copper in order not to have the one bucket
(copper) become too negative and the other bucket (zinc bucket) too positive
Standard Reduction Potential. - ANSWER>>Standard Reduction Potential The
standard reduction potential is the tendency for a chemical species to be reduced and is
measured in volts at standard conditions. The more positive the potential is the more
likely it will be reduced
Which is the ion that is most easily reduced? ANSWER>> Use the reduction potential
chart: all the nonmetals are at the top-most easily reduced all the metals are at the
bottom-most easily oxidized Lithium is at the bottom of the chart-most easily oxidized of
all So order, from easiest to oxidize to hardest to oxidize is Au, Fe, Cu, Ca, Li.
100% VERIFIED SOLUTIONS!!
Electrochemistry - ANSWER>>Electrochemistry is the study of chemical processes that
cause electrons to move. This movement of electrons is called electricity, which can be
generated by movements of electrons from one element to another in a reaction known
as an oxidation-reduction ("redox") reaction
Galvanic (voltaic) cells - ANSWER>>which are thermodynamically favorable chemical
reactions (battery)
Electrolytic cells - ANSWER>>which are thermodynamically unfavorable and require
external e− source (a direct current or DC power source)
balancing redox reactions in an acidic solution - ANSWER>>add h20 to balance O and
H+ to balance the h atoms
balancing redox reactions in an basic solution - ANSWER>>do everything like the acidic
one except at the end for each H+ add an OH- to BOTH SIDES!!!
and combined H+ and OH-to make H2O
and subtract from both sides if possible
the experimental apparatus for generating electricity through the use of a spontaneous
reaction is called a - ANSWER>>galvanic cell or voltaic cell
anode - ANSWER>>anode in a galvanic cell is the electrode at which oxidation occurs
and the cathode is the electrode at which reduction occurs.
oxidation - losing electrons
,the cathode - ANSWER>>the cathode is the electrode at which reduction occurs.
reduction gaining electrons
Salt bridge - ANSWER>>used to maintain electrical neutrality in a galvanic cell; may be
filled with agar which contains a neutral salt
Electron flow - ANSWER>>ALWAYS through the wire from anode to cathode
(alphabetical order)
Voltmeter - ANSWER>>measures the cell potential (emf) in volts.
Inert electrodes - ANSWER>> used when a gas is involved OR ion to ion involved such as
Fe3+ being reduced to Fe2+ rather than Fe0; made of Pt (expensive) or graphite(cheap)
oxidation occurs at the anode (may show mass decrease) - ANSWER>>
which one anode or cathode have mass decreases - ANSWER>> anode
Salt Bridge - ANSWER>>bridge between cells whose purpose is to provide ions to
balance the charge. Usually made of a salt filled agar KNO3) or a porous disk may be
present instead.
EPA - in an electrolytic cell there is a positive anode.
which is more reactive zinc or copper - ANSWER>>Zinc reacts with a solution
containing copper ions. The zinc metal is more reactive than copper metal and so it can
force the copper metal ions to accept electrons and become metal atoms. The zinc
metal passes its electrons to the copper ions.
let say you have copper sulfate in solution which gives Cu⁺² and SO₄⁻²
, before reaction is blue color then with zinc what will the color look like? - ANSWER>>the
zinc since it more reactive than copper will force its electrons on it thus copper will be
natural
and ZnSO₄²⁻ will form
copper will become the ppt
before reaction is blue color then with zinc what will the color look like
colorless
the zinc was being oxide and copper was being reduce
Has does the salt bridge work with the zinc and copper example
Remember copper becomes Cu cause it gains the two electrons from zinc who's is more
reactive than copper - ANSWER>>you will have two buckets one with copper and other
will zinc (in individual buckets)
the zinc electron go through the wire and make the copper neutral the salt brige comes
in made of example Na₂SO₄⁻²
so the SO₄⁻² reacts with the Zn²⁺
sodium might go in the copper to neutral the copper in order not to have the one bucket
(copper) become too negative and the other bucket (zinc bucket) too positive
Standard Reduction Potential. - ANSWER>>Standard Reduction Potential The
standard reduction potential is the tendency for a chemical species to be reduced and is
measured in volts at standard conditions. The more positive the potential is the more
likely it will be reduced
Which is the ion that is most easily reduced? ANSWER>> Use the reduction potential
chart: all the nonmetals are at the top-most easily reduced all the metals are at the
bottom-most easily oxidized Lithium is at the bottom of the chart-most easily oxidized of
all So order, from easiest to oxidize to hardest to oxidize is Au, Fe, Cu, Ca, Li.
