Chemical Process

Phosphorus is a nonmetallic chemical element that is a member of Group VA in the periodic table. The chemical symbol for phosphorus is P , its atomic number is 15, and its atomic weight is 30.975. Phosphorus was first prepared by German alchemist Hennig Brandt in 1669, in the course of his search for the philosopher's stone he obtained from a residue of evaporated urine a white solid that glowed in the dark and ignited spontaneously in air. The name phosporus (from the Greek for "light bringing"), which at that time was used for any substance that glows of itself, was eventually appropriated to this element. Phosphorus does not occur in elemental form in nature; it is found most commonly in apatite minerals such as fluorapatite. There are white phosphorus, black phosphorus and red phosphorus. Red phosphorus is considered as mixture of black phosphorus and white phosphorus. See the picture of each kind of phosphorus: White phosphorus Red phosphorus Black P

Arsenic is a metallic chemical element in Group VA of the periodic table. Its symbol is As, its atomic number is 33, and its atomic weight is 74.9216. The Earth's crust contains only about 5.5 parts arsenic per million, but it occurs in many minerals. Arsenic exist in three allotropic modifications, the yellow (alpha) and the black (betha) and metallic, or gray (gamma). Normally arsenic is found in its metallic form, which is the most stable and its normal pressure does not melt but sublimes at about 615 o C. It forms alloy with other metalls. The alpha and betha modifications have no metallic properties. Arsenic is fairly reactive. Above 400 o C it burns with a bluish flame, forming arsenic trioxide, As2O3. This compound is know as white arsenic and is used as a rat poison. The toxic quality of arsenic has been known since ancient times. In the human body it accumulates in the nails and the hair, where it can be detected, even in the bodies of persons long dead, by the atomic

For field engineer that usually measure a pH of the liquid on the environment that they are founded, they usually use portable pH meter in order can easily to check the pH condition of the liquid flow. The Model Personal pH/ORP Meter is a highly accurate, portable pH meter for laboratory and field application. With its self-diagnostic function, the PH meter provides precise measurement of pH and ORP (oxidation-reduction potential). Measurement results can be stored and stored data can be checked on the meter display any time. The PHmeter is of waterproof construction so that it can safely be used outdoors on a rainy day, and can also withstand being accidentally dropped into water. Some Feature should be own by pH meter equipment: Water resistant case Simple calibration Automatic calibration based on preprogrammed data of standard solutions or manual calibration can be done through simple key operations. Calendar and clock function Internal clock functions allow “one-touch

Numerical characteristic of hydrogen are summarized on the below table. The values on the latter table are for the ordinary isotropic mizture of hydrogen containing about one part of deuterium in 5000 and the ordinary ortho para mixture. Numerical Constant of Hydrogen Property Numerical Value Critical Temperature, o K 32 Critical pressure, atm 20 Density of gas, gram/liter at 0 o C, 1 atm 0 Density of liquid, gram/ml 0.071 Solubility in H 2 O, ml/100 grams as 25 o C 1.5 Chemically, hydrogen combines with most, of the non metallic elements and with many of the metals to produce compounds called hydrides. Hydrogen serves as a reducing agent toward many metal oxides oxides and toward double and triple bounds involving carbon. Characteristic reactions of hydrogen, in general reaction are indicative of the tendency of hydrogen to bonds with highly electropositive elements are completely ionic those with higly electromagnetive posses appreciable partial ionic character.