Electrochemical Cell Potential

What is the relationship between electrical properties and chemical reactions?

What type of energy is converted into electrical energy in a galvanic cell?

What is the charge of the cathode in an electrolytic cell?

What type of reaction occurs in an electrolytic cell?

What is the electrode at which oxidation occurs in an electrochemical cell?

What is the instrument used to measure electrical properties in electrochemical cells?

What type of cell generates a current-potential?

What is the process that occurs at the cathode in an electrochemical cell?

What is the purpose of a voltmeter in an electrochemical cell?

What is the equation to calculate the potential of an electrochemical cell?

What type of electrochemical method measures the conductance of a solution?

What is the purpose of the Nernst equation in potentiometry?

What is the formula to calculate the potential of an electrode at 25°C for a cation?

What is the purpose of an indicator electrode in potentiometry?

What is the classification of electrochemical methods based on?

How many types of electrochemical methods are there?

Electrochemical Cells

Electrochemical cell potential difference (emf) can be experimentally measured using a voltmeter: Ecell = E (cathode) – E (anode) = E (right) – E (left)
Electrode potential of each half cell cannot be experimentally measured but can be calculated using the Nernst equation: Ox + ne- = Red

Classification of Electrochemical Methods

There are three types of electrochemical methods:
- Potentiometry
- Conductimetry
- Voltammetry

Potentiometry

Measures the electrical potential developed by an electrode in an electrolyte solution at zero current flow, using the Nernst equation
Nernst equation relates potential to concentration of analyte: E25°c = E° + (0.0591/n) log [Mn+]
Potentiometric methods are based on measurements of the potential of electrochemical cells in the absence of appreciable currents (i.e. 0)

Conductimetry

Measures the conductance of a solution, which depends on the concentration of its ions, using inert electrodes and alternating current

Electrochemistry

Is the relationship between electrical properties and chemical reactions
Electrical properties measured as: voltage, current, resistance
Measurements are carried out by certain instruments, thus the methods are called instrumental methods

Electrochemical Cells

Divided into two cells: Galvanic cell and Electrolytic cell
Galvanic cell: Chemical energy is converted into electrical energy
Electrolytic cell: Electrical energy is converted into chemical energy

Comparing Galvanic Cell and Electrolytic Cell

Galvanic cell:
- Generates current-potential
- Chemical energy is converted into electrical energy
- Spontaneous reaction to occur
- Cathode is positive (+), Anode is negative (-)
Electrolytic cell:
- Consumes current-potential
- Electrical energy is converted into chemical energy
- Non-spontaneous reaction to occur
- Cathode is negative (-), Anode is positive (+)

Electrodes

Cathode: The electrode at which reduction occurs (gain of electrons), usually metal electrodes
Anode: The electrode at which oxidation occurs (loss of electrons), usually metal electrodes

This quiz covers the measurement of electrochemical cell potential, including the use of voltmeter and Nernst equation. It also explains the calculation of electrode potential and the difference between cathode and anode.