Immersion plating involves depositing a metallic coating on a metal immersed in a liquid solution, without the aid of an external electric current. Also called dip plating.
Isomorphism is the existence of two or more substances that have the same crystal structure, so that they form solid solutions.
Micelle is an electrically charged colloidal particle, usually organic in nature, composed of aggregates of large molecules, e.g., in soaps and surfactants. For aqueous solutions, the hydrophilic end of the molecule is on the surface of the micelle, while the hydrophobic end (often a hydrocarbon chain) points toward the centre.
In 1836 the British chemist John Frederic Daniell (1790-1845) proposed an improved electric cell that supplied an even current during continuous operation. Daniell cell consisted of a glass jar containing copper and zinc electrodes, each immersed in their respective acidic sulphate solutions. The two solutions were separated by a porous clay cylinder separator. It was a galvanic cell in which the spontaneous electrodissolution of zinc and electroplating of copper provided the electrical current.
Zn(s) |
→ | Zn2+ + 2e- |
+0.763 V |
Cu2+ + 2e- |
→ | Cu(s) |
+0.337 V |
Zn(s) + Cu2+ |
→← | Zn2+ + Cu(s) |
+1.100 V |
Dielectric constant or permittivity (ε) is an index of the ability of a substance to attenuate the transmission of an electrostatic force from one charged body to another. The lower the value, the greater the attenuation. The standard measurement apparatus utilises a vacuum whose dielectric constant is 1. In reference to this, various materials interposed between the charged terminal have the following value at 20 °C:
vacuum | 1 |
air | 1.00058 |
glass | 3 |
benzene | 2.3 |
acetic acid | 6.2 |
ammonia | 15.5 |
ethanol | 25 |
glycerol | 56 |
water | 81 |
The exceptionally high value for water accounts for its unique behaviour as a solvent and in electrolytic solutions. Dielectric constant values decrease as the temperature rises.
Millon’s reaction is used for testing proteins by the appearance of red colour which the proteins give by reacting with a solution of mercury in nitric acid.
Molar absorption coefficient (ε) is the absorption coefficient divided by amount-of-substance concentration of the absorbing material in the sample solution (ε = a/c). The SI unit is m2mol-1. Also called extinction coefficient, but usually in units of dm3cm-1mol-1.
Nessler’s reagent is a solution of mercury(II) iodide (HgI2) in potassium iodide and potassium hydroxide named after the German chemist Julius Nessler (1827-1905). It is used in testing for ammonia, with which it forms a brown coloration or precipitate.
Dissociation is the process by which a chemical combination breaks up into simpler constituents as a result of either added energy (dissociated by heat), or the effect of a solvent on a dissolved polar compound (electrolytic dissociation). It may occur in the gaseous, solid, or liquid state, or in a solution.
An example of dissociation is the reversible reaction of hydrogen iodide at high temperatures
The term dissociation is also applied to ionisation reactions of acids and bases in water. For example
which is often regarded as a straightforward dissociation into ions
Generalic, Eni. "Binary solution." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table