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Example Questions
Example Question #2 : Galvanic (Voltai) And Elecrolytic Cells
What is true about the current flow in a galvanic cell?
It flows in the direction of electron flow
Galvanic cells do not have a current
It travels from anode to cathode
It travels from cathode to anode
It travels from cathode to anode
In a galvanic cell, the electrons will flow from the anode to the cathode; however, current travels in the opposite direction of the electrons by convention. In chemical cells, current is defined by the direction in which protons would flow. As a result, current flows from the cathode to the anode.
Keep in mind that reduction occurs at the cathode and oxidation occurs at the anode. Electrons are thus constantly moving from the anode to the cathode. Since the current will be opposite to the flow of electrons, we can conclude that it must flow from cathode to anode.
Example Question #2 : Galvanic (Voltai) And Elecrolytic Cells
The following galvanic cell is created:
Which of the following takes place at the cathode?
Gold ions receive electrons
Copper loses electrons
Gold loses electrons
Copper gains electrons
Gold ions receive electrons
Reduction always takes place at the cathode. This means that a substance is receiving electrons.
In the reaction, the gold ions are receiving electrons in order to create gold atoms. This takes place at the cathode.
Copper ions and gold are products, and will not be oxidized or reduced. Copper is reduced at the anode during this reaction.
Example Question #1 : Cell Potential And Free Energy
1.
2.
3.
What is ? Is reaction 3 spontaneous?
, spontaneous
, nonspontaneous
, nonspontaneous
, spontaneous
, nonspontaneous
There are two concepts to consider in this problem. First, the question asks for the . Reaction 3 has
being reduced so the potential for the half reaction becomes negative.
half reaction appears the same in reaction 3 so the potential is the same. Second, negative voltages indicate non-spontaneity and positive voltages are spontaneous.
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