Question

(This is for a chemical engineering class)

Standard hydrogen electrode and reference electrodes. What are they and why do they matter in electrochemistry?

Answer 1

Standard Hydrogen electrode has the following half cell reaction

2H+ + 2e- ---> H2

in this reaction

two electrons are used

This electrode is used as a reference to measure the potentials of other electrodes

so

the potential for a standard hydrogen electrode is taken as zero

2)

reference electrode is an electrode whose potential is already known

they are mostly used as a reference to find the potential of unknown electrodes

common reference electrodes are

a) standard hydrogen electrode

b) normal hydrogen electrode

c) saturated calomel electrode