Regeneration is the process of restoring an ion exchange medium to a usable state after exhaustion. The cation exchanger is normally regenerated with hydrochloric acid and the anion exchanger with sodium hydroxide.
Hesse’s law says that reaction heat of some chemical change does not depend on the way in which the reaction is conducted, but only on starting and ending system state. Hesse’s law is also known as the law of constant heat summation. Hesse’s law is also known as the law of constant heat summation. The law was first put forward in 1840 by the Swiss-born Russian chemist Germain Henri Hess (1802-1850).
Hesse’s law can be used to obtain thermodynamic data that cannot be measured directly. For example, it is very difficult to control the oxidation of graphite to give pure CO. However, enthalpy for the oxidation of graphite to CO2 can easily be measured. So can the enthalpy of oxidation of CO to CO2. The application of Hess’s law enables us to estimate the enthalpy of formation of CO.
C(s) + O2(g) →← CO2(g) | ΔrH1 = -393 kJ mol-1 |
CO(g) + 1/2O2(g) →← CO2(g) | ΔrH2 = -283 kJ mol-1 |
C(s) + 1/2O2(g) →← CO(g) | ΔrH3 = -110 kJ mol-1 |
The equation shows the standard enthalpy of formation of CO to be -110 kJ/mol.
Hydrosphere (from the Greek for water sphere) is a discontinuous layer of water on, under, and over the Earth's surface. It includes all liquid and frozen surface waters, groundwater held in soil and rock, and atmospheric water vapour. Water continuously circulates between these reservoirs in what is called the hydrologic cycle, which is driven by energy from the Sun.
Reservoir | V / 106 km3 | w / % |
---|---|---|
oceans | 1 370.0 | 97.25 |
ice caps and glaciers | 29.0 | 2.05 |
groundwater | 9.5 | 0.68 |
lakes, rivers | 0.127 | 0.01 |
soil moisture | 0.065 | 0.005 |
atmosphere (as liquid equivalent of water vapour) | 0.013 | 0.001 |
biosphere | 0.0006 | 0.00004 |
TOTAL | 1 408.7 | 100 |
Solid solution is a crystalline material that is a mixture of two or more components, with ions, atoms, or molecules of one component replacing some of the ions, atoms of the other component in its normal crystal lattice.
Solutions are homogeneous mixtures of clean substances. Solutions contain two or more substances mixed in a state of molecular dispersion. Component which is found in solution in greater amount than other components is called a solvent and other components are called dissolved substances. Solution can be unsaturated, saturated and oversaturated.
Indium was discovered by Ferdinand Reich and Hieronymus Theodor Richter (Germany) in 1863. Named after the indicum (colour indigo), the colour it shows in a spectroscope. It is rare, very soft, silver-white metal. Stable in air and water. Dissolves in acids. Metal can ignite and burn. Indium is found in certain zinc ores. Used to coat high speed bearings and as an alloy that lowers the melting point of other metals. Relatively small amounts are used in dental items and in electronic semiconductors.
Kelvin (K) is the SI base unit of thermodynamic temperature.
The kelvin, unit of thermodynamic temperature, is the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. The unit was named after the British scientist Sir. W. Thompson, Lord Kelvin (1824-1907).Spectroscopy is the analysis of the lines of light emitted from excited atoms as the electrons drop back through their orbitals. These lines give the energy and distances of the electronic orbitals.
Sublimation is the conversion of a substance from its solid form directly to its gaseous form without the intervening liquid form. Dry ice (frozen carbon dioxide) sublimates at normal room temperature.
Solution is supersaturated when it contains greater quantity of dissolved substance in itself than it corresponds to solubility of that substance at that temperature. It is said to be in an unstable state, and by shaking the vessel containing that such a solution separation of salt surplus can occur.
Generalic, Eni. "Jednadžba stanja." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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