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In the laboratory, anhydrous sodium sulfate is widely used as an inert drying agent, for removing traces of water from organic solutions. [26] It is more efficient, but slower-acting, than the similar agent magnesium sulfate. It is only effective below about 30 °C (86 °F), but it can be used with a variety of materials since it is chemically ...
The mole is widely used in chemistry as a convenient way to express amounts of reactants and amounts of products of chemical reactions. For example, the chemical equation 2 H 2 + O 2 → 2 H 2 O can be interpreted to mean that for each 2 mol molecular hydrogen (H 2) and 1 mol molecular oxygen (O 2) that react, 2 mol of water (H 2 O) form.
The solubility of a specific solute in a specific solvent is generally expressed as the concentration of a saturated solution of the two. [1] Any of the several ways of expressing concentration of solutions can be used, such as the mass, volume, or amount in moles of the solute for a specific mass, volume, or mole amount of the solvent or of the solution.
To create the solution, 11.6 g NaCl is placed in a volumetric flask, dissolved in some water, then followed by the addition of more water until the total volume reaches 100 mL. The density of water is approximately 1000 g/L and its molar mass is 18.02 g/mol (or 1/18.02 = 0.055 mol/g). Therefore, the molar concentration of water is
One mole of sucrose (sugar) per kilogram of water raises the boiling point of water by 0.51 °C (0.918 °F), and one mole of salt per kg raises the boiling point by 1.02 °C (1.836 °F); similarly, increasing the number of dissolved particles lowers water's freezing point. [155]
Many metals such as the alkali metals react directly with the electronegative halogens gases to form salts. [7] [8] Salts form upon evaporation of their solutions. [9] Once the solution is supersaturated and the solid compound nucleates. [9] This process occurs widely in nature and is the means of formation of the evaporite minerals. [10]
The Avogadro constant, commonly denoted N A [1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 10 23 mol −1 (reciprocal moles). [3] [4] It defines the number of constituent particles in one mole, where the particles in question can be either molecules, atoms, ions, ion pairs, or any other elementary entities.
Sodium tends to form water-soluble compounds, such as halides, sulfates, nitrates, carboxylates and carbonates. The main aqueous species are the aquo complexes [Na(H 2 O) n ] + , where n = 4–8; with n = 6 indicated from X-ray diffraction data and computer simulations.