WorksheetsElectrochemistry
Total questions: 45
Worksheet time: 39mins
Name
Class
Date
1.
What is oxidation number of Cr in Cr2O72-?
a)
-2
b)
+2
c)
+6
d)
+12
2.
What is oxidation number of Fe in FeO ?
a)
+2
b)
-2
c)
0
d)
+1
3.
Which substance is reduced in the following reaction?
NaOH + Li --> LiOH + Na
NaOH + Li --> LiOH + Na
a)
Li
b)
Na
c)
O
d)
H
4.
Which of the following is the balanced half -reaction for the oxidation of Cu to Cu+2?
a)
Cu --> Cu+2
b)
Cu + 2 e- --> Cu+2
c)
Cu --> Cu+2 + 2 e-
d)
Cu - 2e- --> Cu+2
5.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
6.
If in a reaction, copper is reduced; its number of electrons has:
a)
Increased
b)
Decreased
c)
Remained Constant
d)
Varies Randomly
7.
Oxygen always has an oxidation number of...
a)
-1
b)
1
c)
2
d)
-2
8.
What is oxidation number of H in H2O?
a)
0
b)
-2
c)
-1
d)
+1
9.
What is the oxidation number of N in NO2-?
a)
-3
b)
+4
c)
-2
d)
+3
10.
What is oxidation number of O in O2 ?
a)
0
b)
-2
c)
+1
d)
+2
11.
What coefficient would Fe+2 have in the following reaction?
___ Al + ___ Fe+2 → ___ Al+3 + ___ Fe
___ Al + ___ Fe+2 → ___ Al+3 + ___ Fe
a)
1
b)
2
c)
3
d)
6
12.
In electrolytic cell, anode will attract...
a)
Cations
b)
Anions
13.
In electrolysis of 0.001 mol/dm3 aqueous NaCl solution, which ion will be selectively discharged at the anode?
a)
Na + ions
b)
Cl - ions
c)
OH- ions
d)
H+
14.
In electrolytic cell, anode electrode is connected to...
a)
Positive Terminal
b)
Negative Terminal
15.
A group of cells that are connected together
a)
anode
b)
battery
c)
salt bridge
d)
half cell
16.
The process in which electrical energy is used to bring about a chemical change
a)
fuel cell
b)
battery
c)
electrolysis
d)
voltaic cell
17.
An electrochemical cell that is used to convert chemical energy into electrical energy
a)
electrolysis
b)
electrode
c)
voltaic cell
d)
anode
18.
A voltaic cell in which a fuel undergoes oxidation and from which electrical energy is obtained continuously.
a)
battery
b)
fuel cell
c)
salt bridge
d)
anode
19.
The electrode at which reduction occurs
a)
cathode
b)
anode
c)
salt bridge
d)
electrode
20.
A conductor in a circuit that carries electrons to or from a substance other than a metal.
a)
electrode
b)
battery
c)
salt bridge
d)
half cell
21.
If Al is above Co in the activity series of metals, which of the following will occur if Al metal is put into a solution of cobalt nitrate?
a)
a redox reaction takes place
b)
the Al strip dissolves
c)
the Al strip becomes coated with cobalt
d)
all of the above
22.
An iron nail is put into a solution of copper nitrate, iron is above copper in the activity series of metals, what will happen?
a)
iron will be reduced
b)
bubbles of oxygen gas will form on iron nail
c)
the iron nail will become copper plated
d)
no reaction occurs
23.
Which is true about fuel cells
a)
designed so they emit no polllutants
b)
very inexpensive
c)
produces energy in short bursts only
d)
never built or used
24.
Which ion can be most easily oxidized
a)
copper +2
b)
zinc +2
c)
iron +2
d)
calcium +2
25.
Which of the following is true for an electrolytic cell?
a)
changes electrical energy into chemical energy.
b)
used in electroplating
c)
uses an electricity to make a nonspontaneous reaction go
d)
all of the above
26.
What occurs to the mass of copper electrode in the following reaction?
Zn/Zn+2 // Cu+2/Cu
Zn/Zn+2 // Cu+2/Cu
a)
increases
b)
decreases
c)
remains the same
27.
What occurs to the mass of zinc electrode in the following reaction?
Zn/Zn+2 // Ag+1 / Ag
Zn/Zn+2 // Ag+1 / Ag
a)
increases
b)
decreases
c)
remains the same
28.
Which metal is the negative electrode?
Zn/Zn+2 // Cu+2/Cu
Zn/Zn+2 // Cu+2/Cu
a)
zinc
b)
copper
29.
Which metal is reduced?
Zn/Zn+2 // Cu+2/Cu
Zn/Zn+2 // Cu+2/Cu
a)
zinc
b)
copper
30.
What does the double line mean?
Zn/Zn+2 // Cu+2/Cu
Zn/Zn+2 // Cu+2/Cu
a)
anode
b)
cathode
c)
salt bridge
d)
substance in contact
31.
If Na is above Co in the activity series of metals, which of the following will occur if the Mg is put into a solution of CoNO3?
a)
no reaction occurs
b)
The Co+2 loses electrons
c)
the Mg is oxidized
d)
none of the above
32.
If Na is above Co in the activity series of metals, which of the following will occur if the Na is put into a solution of CoNO3?
a)
no reaction occurs
b)
The Co+2 loses electrons
c)
the Na is oxidized
d)
none of the above
33.
Which of the following is true using the following electrochemical reaction:
Mn/Mn(NO3)2 // PBSO4/Pb
Mn/Mn(NO3)2 // PBSO4/Pb
a)
Pb is oxidized
b)
Mn is reduced
c)
A strip of Pb is put into solution of Mn(NO3)2
d)
electrons are lost at the Mn electrode
34.
In a hydrogen-oxygen fuel cell
a)
oxygen is fed into the anode compartment
b)
hydrogen is fed into the cathode compartment
c)
the net reaction forms water
d)
all of the above
35.
The net products that result from the electrolysis of water are?
a)
H2 and OH-
b)
O and H+
c)
H+ and OH-
d)
H2 and O2
36.
Calculate the standard cell potential.
Ni + 2Fe+3 ----> Ni+2 + Fe+2
Ni + 2Fe+3 ----> Ni+2 + Fe+2
a)
1.02 V
b)
-1.02 V
c)
-0.19 V
d)
-0.286 V
37.
Calculate the standard cell potential.
3Mg + 2Al+3 --> 2Al + 3Mg+2
3Mg + 2Al+3 --> 2Al + 3Mg+2
a)
+0.71 V
b)
-0.71 V
38.
Write the total cell reaction
Hint - reverse the oxidized half reaction
Cu +2 + 2e- ----> Cu
Al +3 + 3e- ----> Al
Hint - reverse the oxidized half reaction
Cu +2 + 2e- ----> Cu
Al +3 + 3e- ----> Al
a)
Al + Cu+2---> Al+3 + Cu
b)
2Al + 3Cu+2---> 2Al+3 + 2Cu
c)
Al+3 + Cu---> Al + Cu+2
d)
3Al+3 + 2Cu---> 3Al + 2Cu+2
39.
Which of the following is not a similarity between voltaic and electroytic cells?
a)
electrons flow from anode to cathode
b)
reduction occurs at cathode
c)
oxidation occurs at anode
d)
charges on anode and cathode are the same
40.
Which of the following is a difference between a voltaic and electrolytic cell?
a)
electrons flow from anode to cathode
b)
Charges on anode and cathode are opposites
c)
both are used as batteries
d)
both can be used for metal plating
41.
Which type of electrochemical cell is used as a battery?
a)
voltaic
b)
electrolytic
42.
Which cell has energy coming out?
a)
voltaic
b)
electrolytic
43.
Which cell is not spontaneous?
a)
voltaic
b)
electrolytic
44.
If the cell potential is negative, the reaction is?
a)
a success
b)
spontaneous
c)
not spontaneous
45.
Which cell is used for metal plating?
a)
voltaic
b)
electrolytic
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