Electrochemistry Flashcards
the magnitude of a voltage or current signal originating from an electrochemical cell is related to the activity or concentration of a particular chemical species in the cell
Electrochemistry
involves the measurement of electrical signals associated with chemical system that are incorporated into an electrochemical cell
Electrochemistry
converts chemical energy into electrical energy.
Galvanic cell
are required to complete the circuit between the reference and without contaminating anything.
Liquid junction - also known as a salt bridge
Functions:
It allows electrical contact between the two solutions.
It prevents the mixing of the electrode solutions.
It maintains the electrical neutrality in each half cell as ions flow into and out of the salt bridge.
Liquid junction - also known as a salt bridge
Electrochemical Techniques
Potentiometry
Coulometry
Amperometry
Voltammetry
measurement of a potential or voltage difference between two electrodes immersed in solution under the condition of essentially zero current.
Potentiometry
the measured potential is related to the molar concentration by the____ equation
Potentiometry
Nernst
Potentiometry
ELECTRODES
- responds to changes in the activity of solution measuring electrode
b)Indicator Electrode
Reference Electrode
_____mercury/mercurous chloride
_____overall better and faster
_____
Calomel electrode
Silver/silver chloride
Normal hydrogen electrode
-indicator electrode that can respond to individual types of anions or cations
-very sensitive and selective for the ion it measures
Ion-selective electrode
2 types of Ion-selective electrode
(1) Direct ISE
(2) Indirect ISE
-its ionic selectivity depends on the membrane/barrier composition used
Ion-selective electrode
Ion selective electrodes
a. glass aluminum silicate (____)
b. valinomycin gel (____)
c. organic liquid membrane ion exchangers (_____)
d. gas and enzyme electrodes
Sodium
Potassium
Calcium and Lithium
selective for the detection of hydrogen
ions indicator electrode has a glass membrane
pH electrode
pH electrode
internal reference electrode
Ag/AgCl
pH electrode contained within a plastic jacket.
sodium buffer and permeable membrane (_____)
pCO2 electrode
Teflon silicone