All High School Chemistry Resources
Example Questions
Example Question #1 : Electrochemistry
How does an electrolytic cell differ from a galvanic cell?
Oxidation takes place at the anode in an electrolytic cell, but at the cathode in a galvanic cell
Oxidation takes place at the anode in a galvanic cell, but at the cathode in an electrolytic cell
The cathode is marked negative in an electrolytic cell
The cell potential is positive in an electrolytic cell
The cathode is marked negative in an electrolytic cell
Oxidation always takes place at the anode, regardless of the electrical cell type. The charges on the anode and cathode are reversed between galvanic and electrolytic cells. In electrolytic cells, the cathodes are marked negative and the anodes are marked positive. In galvanic cells, the reverse is true: cathodes are marked positive and anodes are marked negative.
Example Question #2 : Help With Electrolytic Cells
Toward which pole do the electrons travel in an electrolytic cell?
The electrons do not travel; only the protons travel
Towards the anode
Towards the positive pole
More information is needed
Towards the cathode
Towards the cathode
Reduction always occurs at the cathode, and oxidation always occurs at the anode. Since reduction is the addition of electrons, electrons must travel toward the site of reduction.
In an electrolytic cell the negative charge is on the cathode, while the positive charge is on the anode. Since an electrolytic cell requires energy to perpetuate the reaction, we are pushing the electrons against their potential gradient. The electrons, which are negatively charged, are traveling towards the cathode, which is also negatively charged.
Example Question #3 : Electrochemistry
The following reaction below takes place in an electrochemical cell:
Is the cell galvanic or voltaic?
Neither
Electrolytic
Galvanic
Both
Galvanic
Since our overall reaction includes magnesium solid in the reactants, we must invert the first equation, including the sign of the electrical potential.
This cell is galvanic because the electrical potential, , is positive. Galvanic cells involve spontaneous reactions, and therefore, do not need any external energy source to drive the reaction.
Example Question #2 : Electrochemistry
The following reaction below takes place in an electrochemical cell:
Which of the following best describes this cell?
Electrolytic
Galvanic
Neither
Both
Electrolytic
Since our overall reaction includes calcium solid in the reactants, we must invert the second equation, including the sign of the electrical potential.
This cell is electrolytic because the electrical potential, , is negative. Electrolytic cells involve nonspontaneous reactions, and therefore, must have an external voltage source such as a battery to drive their reactions.
Example Question #3 : Help With Electrolytic Cells
Which of the following species would mostly likely be oxidized, if placed in a electrochemical cell with another species?
Using the equation: , for a spontaneous reaction to occur, must be positive. With solid zinc as the reactant, any other solid can act as the product, and still give a positive . This is because, subtracting a negative number will give a positive value.
As a result, the equation,, will become inverted to make the solid zinc a reactant. . Solid zinc will give electrons, and oxidize, to reduce other ions.
Example Question #2 : Help With Electrolytic Cells
For the following reaction to occur does the does the electrochemical cell voltaic or galvanic?
Electrolytic
Galvanic
Neither
Both
Electrolytic
First we must rearrange the reduction potentials so that when added together, they match the reaction that takes place in the electrochemical cell.
In the overall reaction, is in the reactant side, so the equation must be inverted.
Use the equation: to find the .
is product, while is the reactant.
The cell must be electrolytic because the value is negative. This means, this the reaction is a non-spontaneous reaction and need a applied energy source to make the reaction take place.
Example Question #1 : Electrochemistry
How does an electrolytic cell differ from a galvanic cell?
The cell potential is positive in an electrolytic cell
Oxidation takes place at the anode in a galvanic cell, but at the cathode in an electrolytic cell
The cathode is marked negative in an electrolytic cell
Oxidation takes place at the anode in an electrolytic cell, but at the cathode in a galvanic cell
The cathode is marked negative in an electrolytic cell
Oxidation always takes place at the anode, regardless of the electrical cell type. The charges on the anode and cathode are reversed between galvanic and electrolytic cells. In electrolytic cells, the cathodes are marked negative and the anodes are marked positive. In galvanic cells, the reverse is true: cathodes are marked positive and anodes are marked negative.
Example Question #1 : Help With Electrolytic Cells
How does an electrolytic cell differ from a galvanic cell?
Oxidation takes place at the anode in an electrolytic cell, but at the cathode in a galvanic cell
The cell potential is positive in an electrolytic cell
The cathode is marked negative in an electrolytic cell
Oxidation takes place at the anode in a galvanic cell, but at the cathode in an electrolytic cell
The cathode is marked negative in an electrolytic cell
Oxidation always takes place at the anode, regardless of the electrical cell type. The charges on the anode and cathode are reversed between galvanic and electrolytic cells. In electrolytic cells, the cathodes are marked negative and the anodes are marked positive. In galvanic cells, the reverse is true: cathodes are marked positive and anodes are marked negative.