Electrolysis
Redox
Cell EMF
Half-reactions
Spontaneity
100

The electrode in an electrochemical cell in which the reduction reaction occurs.

What is a cathode?

100

A chemical reaction in which the oxidation state in which one or more substances change going from reactant(s) to product(s)

What is an oxidation-reduction (redox) reaction?

100

The equation of Eo cell = Eo cathode - Eo anode

What is the cell potential equation (at standard conditions, SATP)?

100

An equation thst shows either oxidation alone OR reduction alone.

What is a half-cell reaction (half-reaction)?

100

Determine if the reaction is spontaneous or nonspontaneous given that the value of the overall electromotive force (emf) is positive.

What is a spontaneous reaction?

200

Maintains electrical neutrality (prevents permanent accumulation of charges) by allowing the flow of ions between the two electrodes of a voltaic cell (aka galvanic cell).

What is a salt bridge?

200
A substance that gives up electrons, therefore causing another substance to be reduced.
What is a reducing agent?
200

Given the following equation and standard reduction potentials, determine E0 cell Zn(s) + 2H+(aq) ---> Zn2+(aq) + H2(g) 

2H+(aq) + 2e- ---> H2(g); E0 red = 0 V
Zn2+(aq) + 2e- ---> Zn(s); E0 red= -0.76 V

What is E0 cell= +0.76V

E0 Cell Anode: Zn(s) ---> Zn2+(aq) + 2e-; E0 anode = -(-0.76 V) = + 0.76 V

E0 Cell Cathode: 2H+(aq) + 2e- ---> H2(g); E0 red = 0 V

E0 cell = E0 Cell Cathode + E0 Cell Anode = 0 V + 0.76V = +0.76 V

200

This type of solution must be balanced by adding H+ ions and H2O.

What is an acidic aqueous solution?

200

Differentiate between E and E0.

What is E0 indicates emf (voltage difference) under standard conditions (SATP, 25OCelsius and 101.3 kPa) and E indicates emf (voltage) under non-standard conditions?

300

Determine in which electrode of the electrochemical cell would the following reaction will occur:
Zn(s) ---> Zn2+(aq) + 2e-

What is the anode?

300

Determine the change in the oxidation number of Hg and N: 2Hg^2+(aq) +N2H4(aq) ---> 2Hg(l) + N2(g) + 4H+(aq)

What is A. Hg- 2+ to 0 B. N- 2- to 0

300

Given the following reaction and that the standard reduction potential of Zn+2 to Zn is -0.76 V, the E0 red for the reduction of Cu+2 to Cu can be determined

Zn(s) + Cu2+(aq) ---> Zn2+(aq) + Cu(s); E0 cell = 1.10V

What is +0.36 V

Zn(s)|Zn2+(aq)||Cu2+(aq)||Cu(s)

E0 cell = + 1.10 V

E0 Cell Anode: Zn(s) ---> Zn2+(aq) + 2e-; E0 anode = -(-0.76 V) = + 0.76 V

E0 Cell Cathode = E0 Reduction of Cu2+ to Cu:

E0 Cell Cathode = E0 cell - E0 Cell Anode
= 1.10 V - 0.76 V = 0.34 V

300

Determine the number of electrons that must be added to the right side of the reaction to balance the charges: 2Cl-(aq) ----> Cl2(g) + ____

What are 2 electrons?

300

TRUE or FALSE: A salt bridge is REQUIRED for a galvanic/voltaic cell.

True, because the salt bridge is needed to facilitate the flow of ions between the beakers (electrodes) within the galvanic cell, therefore preventing of permanent accumulation of positive or negative charges.  This facilitates the spontaneous chemical reaction to occur to generate positive voltage (aka electromotive force).

400

Ion that moves toward the anode.

What is an anion?

400

A. Complete and balance the following half-reactions. B. Determine whether oxidation or reduction occurs.

TiO2(s) ---> Ti2+(aq) in an acidic solution

What is A. TiO2(s) + 4H+(aq) + 2e- ---> Ti2+(aq) + 2H2O(l) 
B. reduction

400

Determine the half reaction that occurs at the cathode and the half reaction that occurs at the anode given the following Standard Reduction Potentials

Sn2+(aq) + 2e- ---> Sn(s); E0 red = -0.136V

Cd2+(aq) + 2e----> Cd(s); E0 red= -0.403V

What is Anode: Cd(s) ---> Cd2+(aq) + 2e-

Cathode: Sn2+(aq) + 2e- ---> Sn(s)

400

Determine on which side of a reduction reaction the electron appear, left or right.

What is the left side of a reduction reaction, the reactants side?

400

Determine whether or not these reduction reactions are spontaneous:

Cl2(g) + 2e- ---> 2Cl-(aq) E0 = +1.36V

I2(s) + 2e- ---> 2I-(aq)  E0 = +0.54V

What is spontaneous?

*Halogens are electronegative non-metals that would prefer to gain electrons to have full valence shells

500

In the following reaction, determine the electrode which gains mass:

Zn(s) + Cu2+(aq) ---> Zn2+(aq) + Cu(s)

What is the cathode, specifically the Cu(s) electrode.

500

A. Complete and balance the following half-reactions. B. Determine whether oxidation or reduction occurs. La(s) ---> La(OH)3(s) in a basic solution

What is A. La(s) + 3OH-(aq) ---> La(OH)3(s) + 3e- 

B. oxidation

500

Given the following E0 red values, determine if NO3-(aq), Ag+(aq), or Cr2O7(aq)-2 is the strongest oxidizing agent
NO3-(aq) + 4H+(aq) + 3e- ---> NO(g) + 2H2O(l);
E0 red = +0.96V
Ag+(aq) + e- ---> Ag(s); E0 red = +0.80V
Cr2O72-(aq) + 14H+(aq) + 6e- ---> 2Cr+3(aq) + 7H2O(l); E0 cell= 1.33V

What is Cr2O72-(aq)?

*The reduction with the most positive reduction potential is the most keen to be reduced, which simultaneously means that it has the most eager (strongest) oxidizing agent

500
Determine the overall reaction given these two half-reactions: CN- (aq) ---> CNO- (aq) MnO4- (aq) ---> MnO2 (s)
What is 3CN-(aq) + H20(l) + 2MnO4-(aq) --->
500
Determine whether the following reaction is spontaneous under standard conditions. Explain Cu(s) + 2H+ (aq) ---> Cu2+ (aq) + H2(g) 2H+ (aq) + 2e- ---> H2(g); E o red = 0V Cu2+ (aq) + 2e- ---> Cu(s); E o red = +0.34V
What is No because standard EMF for this reaction is negative. In order for the reaction to be a spontaneous process, standard EMF must be positive. Standard EMF= Eo(reduction) - Eo(oxidation)
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