The carbon dioxide ion selective electrode uses a gas-permeable membrane to separate the sample solution from the electrode internal solution. Dissolved carbon dioxide in the sample solution diffuses through the membrane until an equilibrium is reached between the partial pressure of CO2 in the sample solution and the CO2 in the internal filling solution. In any given sample the partial pressure of carbon dioxide will be proportional to the concentration of carbon dioxide. The diffusion across the membrane affects the level of hydrogen ions in the internal filling solution:
The hydrogen level of the internal filling solution is measured by the pH electrode located behind the membrane. The internal filling solution contains a high concentration of sodium bicarbonate (e.g. 0.1 mol/L NaHCO3) so that the bicarbonate level can be considered constant.
Standardisation is a process of determining the exact concentration of secondary standard solution.
Electrodeposition is a process of depositing solid materials on an electrode surface using electrolysis. It is a somewhat loosely used term that is applied to many technologies. There are a number of metal deposition technologies. However, not only metals but also different compounds can be electrodeposited. This is used most often for the formation of oxides (such as manganese dioxide and lead dioxide) by anodic oxidation of dissolved salts.
Electrodialysis is a procedure of dialysis accelerated with an electric field. Dialyser is divided into three sections. Solution flows through the middle section, between two semipermeable membranes alternately to positive ions and negative ions. An electrodes are placed in the neighbouring sections. Under the influence of electric field, positive ions will travel towards the cathode (the negative electrode), and negative ions towards the anode (the positive electrode), whereby travelling of ions through the membrane is accelerated. In this way, the feed water is separated into two streams: one of pure water and the other of more concentrated solution.
Electrochemical series is a series of chemical elements arranged in order of their standard electrode potentials. The hydrogen electrode
is taken as having zero electrode potential. An electrode potential is, by definition, a reduction potential.
Elements that have a greater tendency than hydrogen to lose electrons to their solution are taken as electropositive; those that gain electrons from their solution are below hydrogen in the series and are called electronegative.
The series shows the order in which metals replace one another from their salts; electropositive metals will replace hydrogen from acids.
Redox potential is the potential of a reversible oxidation-reduction electrode measured with respect to a reference electrode, corrected to the hydrogen electrode, in a given electrolyte.
1. Atmosphere is the column of air which is extending several hundred kilometers above the surface the Earth's surface. The density of this air decreases as you proceed up from the surface. The air in the atmosphere consists of 78 % nitrogen, 21 % oxygen, and 0.9 % argon. The remaining 0.1 % of the atmosphere consists of ozone, water vapor, carbon dioxide, methane, helium, and neon. The atmosphere is divided into different regions. The lowest two layers are the troposphere (the layer closest to the earth) and the stratosphere respectively. These two layers contain more than 99 % of the atmospheric molecules.
2. Standard atmosphere (atm) is an obsolete pressure and stress unit which should be discontinued. It is unit of pressure equal to the air pressure measured at mean sea level.
1 atm = 101 325 Pa
Technical atmosphere (at) is an obsolete MKpS pressure and sttress derived unit.
1 at = 98 066.5 Pa
1 atm = 1.033 227 453 at
Atmospheric pressure is the pressure exerted by weight of the air above it at any point on the earth’s surface. At sea level the atmosphere will support a column of mercury about 760 mm high. This decreases with increasing altitude. The standard value for the atmospheric pressure at sea level in SI units is 101 325 Pa.
Generalic, Eni. "Standard hidrogen electrode." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table