![]() ![]() The protein cauxin, a protein excreted in large amounts in cat urine that acts to produce a feline pheromone, has recently been found to cause nucleation of struvite crystals in a model system containing the ions necessary to form struvite. Urea-splitting organisms include Proteus, Xanthomonas, Pseudomonas, Klebsiella, Staphylococcus, and Mycoplasma.Įven in the absence of infection, accumulation of struvite crystals in the urinary bladder is a problem frequently seen in housecats, with symptoms including difficulty urinating (which may be mistaken for constipation) or blood in the urine ( hematuria). Struvite stones are potentiated by bacterial infection that hydrolyzes urea to ammonium and raises urine pH to neutral or alkaline values. Struvite is the most common mineral found in urinary tract stones in dogs, and is found also in urinary tract stones of cats and humans. Struvite precipitates in alkaline urine, forming kidney stones. A simple test can differentiate struvite from glass. Struvite is occasionally found in canned seafood, where its appearance is that of small glass slivers, objectionable to consumers for aesthetic reasons but of no health consequence. Similar conditions are found when human bladders are infected by urease-producing bacteria, when wastewater is treated, etc. In nature, it forms primarily in areas associated with organic matter decomposition, including guano deposits, basaltic caves, and marshlands. Struvite readily forms in alkaline conditions where its constituent ions are present. They also are potentiated by a specific urinary protein in domestic cats.Īlthough struvite was briefly mentioned in Hooke's Micrographia, it was first described in detail in 1845 by the German chemist Georg Ludwig Ulex (1811–1883), who found crystals of struvite in what he surmised had once been a medieval midden in Hamburg, Germany he named the new mineral after the geographer and geologist Heinrich Christian Gottfried von Struve (1772–1851) of Hamburg. They are potentiated by alkaline urine and high magnesium excretion (high magnesium/plant-based diets). Struvite urinary stones and crystals form readily in the urine of animals and humans that are infected with ammonia-producing organisms. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. Struvite ( magnesium ammonium phosphate) is a phosphate mineral with formula: NH 4MgPO 4♶H 2O. Slightly soluble, dehydrates in dry, warm air For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass.Colorless, white (dehydrated), yellow or brownish, light gray This is not the same as molecular mass, which is the mass of a single molecule of well-defined isotopes. This is how to calculate molar mass (average molecular weight), which is based on isotropically weighted averages. The atomic weights used on this site come from NIST, the National Institute of Standards and Technology. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula. When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.įinding molar mass starts with units of grams per mole (g/mol). This site explains how to find molar mass. The reason is that the molar mass of the substance affects the conversion. To complete this calculation, you have to know what substance you are trying to convert. These relative weights computed from the chemical equation are sometimes called equation weights.Ī common request on this site is to convert grams to moles. ![]() The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.įormula weights are especially useful in determining the relative weights of reagents and products in a chemical reaction. If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. ![]() ![]() In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together. ![]()
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