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Anhydrous aluminium chloride is hygroscopic, having a very pronounced affinity for water. It fumes in moist air and hisses when mixed with liquid water as the Cl − ligands are displaced with H 2 O molecules to form the hexahydrate [Al(H 2 O) 6]Cl 3. The anhydrous phase cannot be regained on heating the hexahydrate.
Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. Acid rain has been shown to have adverse impacts on forests, freshwaters, soils, microbes, insects and aquatic life ...
The strength of the bonds between the metal ion and water molecules in the primary solvation shell increases with the electrical charge, z, on the metal ion and decreases as its ionic radius, r, increases. Aqua ions are subject to hydrolysis. The logarithm of the first hydrolysis constant is proportional to z 2 /r for most aqua ions.
Both compound classes are hydrophobic and therefore virtually insoluble in water - the solubility of the commonly used iso-octadecenylsuccinic anhydride (C 18-ASA) is only 5.33x10 −5 mgl −1. ASA are less hydrophobic and thus less water repellent than AKD because of their shorter chain length.
The water molecule is amphoteric in aqueous solution. It can either gain a proton to form a hydronium ion H 3 O +, or else lose a proton to form a hydroxide ion OH −. [7] Another possibility is the molecular autoionization reaction between two water molecules, in which one water molecule acts as an acid and another as a base. H 2 O + H 2 O ...
Typically anhydrous solvents will contain approximately 10 ppm of water and will increase in wetness if they are not properly stored. Organic solutions can be dried using a range of drying agents . Typically following a workup the organic extract is dried using magnesium sulfate or a similar drying agent to remove most remaining water.
When a solution of an acid, HA, is at equilibrium, by definition the concentrations are related by the expression [A − ][H + ] = K a [HA]; p K a = − log K a The solvent (e.g. water) is omitted from the defining expression on the assumption that its concentration is very much greater than the concentration of dissolved acid, [H 2 O] ≫ T A .
Mechanism for acid-catalyzed hydrolysis of an amide. Upon hydrolysis, an amide converts into a carboxylic acid and an amine or ammonia (which in the presence of acid are immediately converted to ammonium salts). One of the two oxygen groups on the carboxylic acid are derived from a water molecule and the amine (or ammonia) gains the hydrogen ion.