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Phosphorus has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). It is not found free in nature, but is widely distributed in many minerals, usually as phosphates. [12]
The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol ≈ 1 g/mol. For normal samples from Earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight [ 2 ] or the conventional atomic weight.
The molar mass is defined as the mass of a given substance divided by the amount of the substance, and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different isotopes), and the molecular mass the mass of one specific particle or molecule. The molar mass is ...
Molar mass: 30.974 g·mol −1 Density: 2.34 g/cm 3: Melting point: 590 °C (1,094 °F; 863 K) Hazards ... Red phosphorus is an allotrope of phosphorus. It is an ...
Because a dalton, a unit commonly used to measure atomic mass, is exactly 1/12 of the mass of a carbon-12 atom, this definition of the mole entailed that the mass of one mole of a compound or element in grams was numerically equal to the average mass of one molecule or atom of the substance in daltons, and that the number of daltons in a gram ...
The phosphate ion has a molar mass of 94.97 g/mol, and consists of a central phosphorus atom surrounded by four oxygen atoms in a tetrahedral arrangement. It is the conjugate base of the hydrogen phosphate ion H(PO 4) 2−, which in turn is the conjugate base of the dihydrogen phosphate ion H 2 (PO 4) −
However, one gram of hydrogen reacts with 8 grams of oxygen to give water or with 35.5 grams of chlorine to give hydrogen chloride: hence 8 grams of oxygen and 35.5 grams of chlorine can be taken to be equivalent to one gram of hydrogen for the measurement of equivalent weights. This system can be extended further through different acids and bases.
White phosphorus is reduced by sodium-potassium alloy: [6] P 4 + 12 Na → 4 Na 3 P. Phosphorus reacts with sodium in an autoclave at 150 °C for 5 hours to produce Na 3 P. [7] Alternatively the reaction can be conducted at normal pressures but using a temperatures gradient to generate nonvolatile Na x P phases (x < 3) that then react further ...