Understanding Cell Potentials in Electrochemical Cells

This video tutorial explains how to calculate the cell potential for galvanic and electrolytic cells. It covers the importance of having a positive cell potential in galvanic cells and demonstrates how to adjust half reactions to achieve this. The tutorial also discusses the calculation of cell potentials for phonic and electrolytic cells, emphasizing the need to ensure electrons are on opposite sides and the overall reaction is balanced. The video provides examples and explains the concept of non-spontaneous reactions in electrolytic cells, highlighting the minimum voltage required to drive such reactions.

What is the requirement for the cell potential in a galvanic cell?

• It must be negative.

• It must be zero.

• It must be positive.

• It can be any value.

Why is it necessary to adjust half-reactions in a galvanic cell?

• To ensure the cell potential is positive.

• To make sure electrons are on the same side.

• To increase the number of electrons.

• To ensure the cell potential is negative.

What happens to the cell potential if you multiply a half-reaction by a factor?

• It doubles.

• It remains unchanged.

• It becomes zero.

• It halves.

In a galvanic cell, what must occur for the electrons in half-reactions?

• They must be on the same side.

• They must cancel out.

• They must be added.

• They must be multiplied.

What is the lowest possible cell potential for a galvanic cell?

• Negative

• Zero

• Positive

• Any value

How can the cell potential of an electrolytic cell be described?

• Always positive

• Always zero

• Can be positive or negative

• Always negative

What is the role of standard reduction potentials in calculating cell potential?

• They are not used.

• They are only used for electrolytic cells.

• They determine the spontaneity of the reaction.

• They are only used for galvanic cells.

What is required to drive a non-spontaneous reaction in an electrolytic cell?

• External energy

• A higher temperature

• No energy

• A lower voltage

What is the minimum voltage needed to drive a non-spontaneous reaction in an electrolytic cell?

• Equal to the cell potential

• Less than the cell potential

• Greater than the cell potential

• Zero

Why might a higher voltage than the minimum be required in an electrolytic cell?

• To decrease the reaction rate

• To reduce the cell potential

• To compensate for energy loss due to friction

• To increase the reaction rate