Chapter 19 Practice Test Flashcards
What is the common oxidation number for oxygen in a compound?
-2
What is the oxidation number for nitrogen in Cu(NO3 )2 for the following reaction?
+5
Which of the following is the balanced equation for the reaction between the permanganate ion and chloride ion in an acidic solution?
MnO4- + Cl- -> Mn2+ + Cl2
2MnO4- + 10Cl- + 16 H+ -> 2Mn2+ + 5Cl2 + 8H2O
In the diagram of an galvanic cell, which is the anode?
A
In the following reaction, which half reaction would take place at the anode?
Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)
Zn(s) → Zn2+ (aq) + 2e−
In the diagram of an electrolytic cell, where is oxidation taking place?
A
One compartment of a galvanic cell contains a zinc strip in a solution of Zn(NO3 )2. The other compartment contains a nickel strip in a solution of NiCl2. Which reaction occurs at the anode and which reaction occurs at the cathode?? In this cell, the standard reduction potential for zinc is −0.76 V and the standard reduction potential for nickel is −0.23 V
Anode Reaction: Zn -> Zn2+ + 2e-
Cathode Reaction: Ni2+ + 2e- -> Ni
Which of the following can be done to make a cell with a higher EMF?
Use different metals
Which unit is used to measure electromotive force(EMF)?
volts
The standard potential of the tin ion (Sn2+) is -0.14 V
Sn2+(aq) + 2e- -> Sn(s)
What is the standard oxidation potential of the tine (Sn(s))?
+0.14 V
Which of the following species is the strongest oxidizing agent?
Reduction half-reaction:
Au3+ + 3e−
Standard reduction potential:
+1.42 V
Study the series of the standard aqueous electrode potentials at 25°C. Which is the strongest reducing agent in the group?
Lithium
Using the table below, place the following in order of decreasing strength as oxidizing agents:
Fe2+, ClO2, F2, AgCl
F2 > ClO2 > AgCl > Fe2+
Calculate the standard Gibbs free energy change in J / mol at 25°C for the following reaction:
3Sn4+ + 2Cr -> 3Sn2+ + 2Cr3+
−5.2 × 10^5 J / mol
Calculate the equilibrium constant for the following reaction at 25°C, given that
E°cell = +0.99 V
3Cu(s) + Cr2O72-(aq) + 14H+(aq) –> 3Cu2+(aq) + 2Cr3+(aq) + 7H2O(l)
2.18 × 10^100
How many half-reactions occur when a car battery discharges?
Two
When does equilibrium occur in a battery?
Ecell = 0.
What is the acid found in a lead-acid (storage) battery?
Sulfuric acid
Which acid-base reaction occurs in a Leclanché cell?
NH4+ reacting with OH −
Under anaerobic conditions, which of the following can oxidize iron?
H2O
Which reaction best represents the formation of rust?
2Fe(OH)3(s) -> Fe2O3 * H2O(s) + 2H2O(l)
Which of the following is the product of reduction in an electrolytic cell with molten NaCl?
Na
In the diagram of an electrolytic cell, which is the anode?
A
Consider the electrolytic process below
Cu2+(Aq) + 2e- -> Cu(s)
How many grams of copper are produced when a current of 10.0 amps is passed for 0.5 hours through a solution containing copper (II) ions?
5.94 g
Use the table of standard reduction potentials to calculate the Ecell for the following reaction in a galvanic cell:
Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)
+1.10 V
