![]() For instances ordinary soap dissolved in water diffuses very slowly and cannot penetrate a membrane, showing it to be a colloid but in alcohol solution the same soap possesses the properties of a crystalloid.Thus, the sharp demarcation line between crystalloids and colloids gradually disappeared, and at present we can speak only of the crystalloid or colloid states of substances, just as we have spoken above of their solid and liquid states.The colloid state of substances plays a very important part not only in chemistry, but also in biology, medicine, technology and agriculture, and therefore we shall dwell on it in some detail.189. Further investigations confirmed this assumption and led to the conclusion that Grahams division of substances into crystalloids and colloids should be rejected, as not only such typical colloids as albumen could be obtained in the form of crystals, but many indisputable crystalloids, such as common salt, could be obtained in the form of colloids.Finally, it was proved that the same substance could behave like a colloid in some solvents and like a crystalloid in others. Borshchov put forth the assumption that the particles of certain colloids may also be of crystalline structure. On this basis Graham called the former crystalloids and the latter colloids (from the Greek "colla"- glue).However, as early as 1869, the Russian botanist I. On the contrary, substances which could not diffuse through membranes were found to be amorphous, and formed shapeless (and to a certain degree plastic) masses when isolated from solution. Graham found that all substances capable of diffusing in solution are crystalline in the solid state. As a result, the cylinder will be found after some time to contain a pure solution of silicic acid.The method of separating dissolved substances based on the fact that one of them will not diffuse through a membrane, is known as dialysis, and the apparatus described is called a dialyzer.Many other dissolved substances, besides silicic acid, viz., glue, gelatin, egg albumen, etc., cannot penetrate a membrane of parchment paper or bladder.In the sixties of the last century the diffusion of dissolved substances through vegetable and animal membranes was studied in detail by the English chemist Graham. The sodium chloride and hydrochloric acid diffuse freely through the membrane into the outer vessel, but the silicic acid cannot penetrate the membrane and remains in solution. The cylinder is submerged in a wider vessel containing water which is continuously renewed. ![]() ![]() The solution is placed in a bottomless cylinder with a membrane of parchment paper or an animal bladder bound over its end. If a solution of sodium silicate is added to concentrated hydrochloric acid, the resulting silicic acid does not separate out as precipitate but remains in solution together with the sodium chloride formed during the reaction.The hydrochloric acid and sodium chloride can be removed from the solution in the following way. Crystalline and Colloid States of Substances. Glinka,Peace Publishers, Moscow, circa 1960s188. Thanks to FM capture effect, Frequency Modulated broadcasts mayīe jammed, unnoticed, by a simple unmodulated carrierĬolloids & The Tyndall Effectfrom General Chemistryby N. Often technical attacks on modern equipment, such as "squelch The radio does not receive incoming signalsĮverything seems superficially normal to the operator. Subtle jamming is jamming during which no sound is heard on the Noise from the diesel generator that was powering the jamming Transmitted signals and to cause a nuisance to the receivingĮarly Soviet attempt at jamming western broadcasters used the The purpose of this type of jamming is to block out reception of Traditional Chinese music while it is jamming channels. ForĮxample, China, which used jamming extensively and still does, To be identified in order to assess their effectiveness. Various combinations of these methods may be used oftenĪccompanied by regular Morse identification signal to enable Obvious jamming is easy to detect because it can be heard on the These can be divided into two groups - obvious and subtle. The most common types of this form of signal jamming are Power, override any signal at the receiver. Receiving equipment and with the same type of modulation, can, with Intentional communications jamming is usually aimed at radioĪ transmitter, tuned to the same frequency as the opponents'
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