Activity coefficient (γ or f) is a fractional number which, when multiplied by the molar concentration of a substance in solution, yields the chemical activity. This term gives an idea of how much interaction exists between molecules at higher concentration.
In solutions of very low ionic strength, when m is less than 0.01, the Debye-Hückel limiting law can be used to calculate approximate activity coefficients
where γi = activity coefficient of the species i, zi = charge on the species i and μ = ionic strength of the solution.
Aluminate is a salt formed when aluminium hydroxide or y-alumina is dissolved in solutions of strong bases, such as sodium hydroxide. Aluminates exist in solutions containing the aluminate ion, commonly written [Al(OH)4]-. In fact the ion probably is a complex hydrated ion and can be regarded as formed from a hydrated Al3+ ion by removal of four hydrogen ions:
Other aluminates and polyaluminates, such as [Al(OH)6]3- and [(HO)3AlOAl(OH)3]2-, are also present.
Amount concentration (also called molar concentration and in older literature molarity) is the amount of a given substance in a stated unit of a mixture, solution, or ore. The common unit is mole per cubic decimetre (moldm−3) or mole per litre (molL-1) sometimes denoted by M.
The concentration of an atom, ion, or molecule in a solution may be symbolised by the use of square brackets, as [Ca2+].
Battery acid is a solution of approximately 6 mol L-1 sulphuric acid used in the lead storage battery
Buffer is a solution designed to maintain a constant pH when small amounts of a strong acid or base are added. Buffers usually consist of a fairly weak acid and its salt with a strong base. Suitable concentrations are chosen so that the pH of the solution remains close to the pKa of the weak acid.
Buffer capacity is number of moles of a strong acid or a strong base needed to change pH of 1 dm3 of buffer solution for pH unit.
Calorimetry is a measurement of the amount of heat evolved or absorbed in a chemical reaction, change of state, or formation of a solution, or any other event that includes heat transfer.
Analytical balances are instruments used for precise determining mass of matter. Analytical balances are sensitive and expensive instruments, and upon their accuracy and precision the accuracy of analysis result depends. The most widely used type of analytical balances are balances with a capacity of 100 g and a sensitivity of 0.1 mg. Not one quantitative chemical analysis is possible without usage of balances, because, regardless of which analytical method is being used, there is always a need for weighing a sample for analysis and the necessary quantity of reagents for solution preparation.
The working part of the balance is enclosed in a glass-fitted case. The baseplate is usually of black glass or black slate. The beam has agate knife-edges at its extremes, supporting stirrups from which balance pans are suspended. Another agate or steel knife-edge is fixed exactly in the middle of the beam on its bottom side. This knife-edge faces downwards and supports the beam. When not in use and during loading or unloading of the pans, the balance should be arrested.
The principle of operation of a modern laboratory balance bears some resemblance to its predecessor - the equal arm balance. The older instrument opposed the torque exerted by an unknown mass on one side of a pivot to that of an adjustable known weight on the other side. When the pointer returned to the center position, the torques must be equal, and the weight was determined by the position of the moving weights.
Modern electronic laboratory balances work on the principle of magnetic force restoration. In this system, the force exerted by the object being weighed is lifted by an electromagnet. A detector measures the current required to oppose the downward motion of the weight in the magnetic field.
Autocatalysis is a reaction in which its product can act as a catalyst. Oxalate oxidation with permanganate in an acid solution is a slow reaction
Mn2+-ions catalyse this reaction. When enough Mn2+-ions are created, the reaction occurs instantly.
Generalic, Eni. "Binary solution." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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