Galvanic Cells

What are galvanic cells used for?

Source of electrical energy, batteries

How is the potential cell difference of a galvanic cell calculated?

. E0 = E0 reduction - E0 oxidation

What is oxidation?

Oxidation is the loss of electrons

What occurs at the cathode?

Reduction (gain of electrons) occurs at the cathode

What is a galvanic cell?

A cell in which spontaneous oxidation-reduction reactions produce electrical energy

What type of chemical reaction occurs in a galvanic cell, Spontaneous, or non-spontaneous?

Spontaneous

What type of electrochemical cell contains a salt bridge?

Galvanic cell

What industrial situations use electrolytic cells?

Some examples of industrial situations in which electrolytic cells would be of use include metal plating and copper purifications.

What are Eo values?

The symbol represents the Cell Potential. It shows the voltage produced in a Galvanic half-cell.

Eo values are measured under specific conditions. What are they?

1M concentration of electrolyte, 298K and 1 atmosphere

Why is molten electrolysis rarely seen/used?

It requires a large amount of energy to both run the cell as well as to keep the solution molten.

In an electrolytic cell what charge does the anode have?

The anode has a positive charge.

What type of electrochemical cell uses energy from an external source?

Electrolytic cell

What are electrolytes?

An ionic substance which is either molten or an aqueous solution

What type of electrode is needed for a molten electrolytic cell?

The electrode must be an inert material; have a higher melting point then the molten solution

What type of reaction occurs in electrolytic cells?

A forced non-spontaneous reaction.

What charge does the cathode have in an electrolytic cell?

The cathode has a negative charge in electrolytic cells

What type of a reaction occurs in a Galvanic cell?

A spontaneous REDOX reaction

What is an external circuit in a Galvanic cell?

Wires that connect the anode to the cathode and allow the movement of electrons to occur

What is the job of the salt bridge in a Galvanic cell?

It is a connection between the 2 half cells that allows the movement of charged ions

What is electrolysis?

The process by which electrical energy is passed into a cell to cause a non-spontaneous reaction to occur

Why does a Galvanic cell need to be separated into two half cells?

In order to utilise the current produced and start or stop the spontaenous reaction

What is an electrode?

A solid conductor of electricity

What are standard conditions under which standard electrode potentials are measured?

250C, 1 atm and 1M

In an electrolytic cell what charge does the anode have?

positive

In a Galvanic cell, what charge does the anode have?

Negative

What is an electrolyte?

A solution that contains positive ions (cations) and negative ions (anions)

Are the strongest reducing agents positive or negative?

Negative

Standard electrode potentials are generally written as?

Reduction half equation

Define the standard electrode potential of a half-cell (Eθ)?

The standard electrode potential of a half-cell is the voltage of a half-cell compared with a standard hydrogen electrode.

What are the units for standard electrode potentials?

Volts (V)

What equation calculates the overall cell potential?

The cell potential is the difference between the reduction potentials: Eocell=Eored−Eooxid

What is the standard electrode potential of a half-cell a measure of?

This potential is a measure of the energy per unit charge which is available from the oxidation/reduction reactions to drive the reaction

What is the difference between cell potential and standard cell potential?

"The cell potential is the measure of the potential difference between two half cells in an electrochemical cell.

A cell's standard potential is the potential of the cell under standard state conditions"

What does Eθ have to equal to be considered a spontaneous reaction?

Positive Value

Name the two types of electrochemical cells.

Galvanic and electrolytic