Why is reference electrode required for pH measurement?
For a pH electrode to provide a voltage measurement of a solution’s ion concentration, a reference electrode is necessary because its potential essentially remains constant and independent of the solution and temperature relative to the solution being measured.
Is a pH electrode a reference electrode?
A typical pH electrode consists of several unique structures, each of which can be seen in Figure 1. The principle components are the electrode body, pH-sensitive glass membrane, reference electrode (i.e. reference system), reference electrolyte, and the reference junction.
What is the standard reference electrode?
A standard reference electrode is an electrode that has a known electrical potential. A standard reference electrode has many uses, but the most common is when it is used to determine the potential of another material in an electrochemical cell.
What is reference electrode and indicator electrode?
The key difference between indicator electrode and reference electrode is that indicator electrode responds to changes in the activity of the analyte, whereas reference electrode does not respond to changes, and its response is stable.
How does a severinghaus electrode work?
The Severinghaus electrode is a modified glass electrode; The electrode contains some sodium bicarbonate, which reacts with the CO2; The reaction changes the pH in the electrode, which corresponds to a change in potential difference, and this is measured. The CO2 is then inferred from the change in pH.
Can glass electrode be used as reference electrode?
A second electrode is necessary when measuring the electromotive force generated at the electrode membrane of a glass electrode. This other electrode, paired with the glass electrode, is called the reference electrode. The reference electrode must have extremely stable potential.
How do you use a pH electrode?
Place the electrode in the correct buffer solution and press measure to take the reading. Rinse and dry the electrode well. Now, place the electrode in the sample, press the measure button, and keep it for about two minutes. This is your pH reading.
What makes a good reference electrode?
Everyone agrees that an ideal reference electrode has a stable, well-defined electrochemical potential. Common reference electrodes (SCE, Ag/AgCl, Cu/CuSO4) meet this criterion when they are functioning properly.
How does reference electrode work?
A reference electrode is an electrode which has a stable and well-known electrode potential. The high stability of the electrode potential is usually reached by employing a redox system with constant (buffered or saturated) concentrations of each participant of the redox reaction.
What is reference electrode used for?
The purpose of the reference electrode is to provide a stable potential for controlled regulation of the working electrode potential and in doing so allow the measurement of the potential at the working electrode without passing current through it. An ideal reference electrode should also have zero impedance.
What is an example of reference electrode?
It is an electrode whose potential is arbitrarily taken as zero or is exactly known. Standard Hydrogen Electrode (SHE), calomel electrode, silver-silver chloride electrode and glass electrode are some examples of reference electrode.