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It is manufactured by treating an aqueous solution of potassium carbonate or potassium hydroxide with carbon dioxide: [1] K 2 CO 3 + CO 2 + H 2 O → 2 KHCO 3. Decomposition of the bicarbonate occurs between 100 and 120 °C (212 and 248 °F): 2 KHCO 3 → K 2 CO 3 + CO 2 + H 2 O. This reaction is employed to prepare high purity potassium carbonate.
The modern commercial production of potassium carbonate is by reaction of potassium hydroxide with carbon dioxide: [3] 2 KOH + CO 2 → K 2 CO 3 + H 2 O. From the solution crystallizes the sesquihydrate K 2 CO 3 ·1.5H 2 O ("potash hydrate"). Heating this solid above 200 °C (392 °F) gives the anhydrous salt.
The tables below provides information on the variation of solubility of different substances (mostly inorganic compounds) in water with temperature, at one atmosphere pressure.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
The temperature of the solution eventually decreases to match that of the surroundings. The equilibrium, between the gas as a separate phase and the gas in solution, will by Le Châtelier's principle shift to favour the gas going into solution as the temperature is decreased (decreasing the temperature increases the solubility of a gas).
The standard Gibbs free energy of formation (G f °) of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).
Potassium hypochlorite is produced by the disproportionation reaction of chlorine with a solution of potassium hydroxide: [2] Cl 2 + 2 KOH → KCl + KOCl + H 2 O. This is the traditional method, first used by Claude Louis Berthollet in 1789. [3] Another production method is electrolysis of potassium chloride solution.
Removal of the BOC group in amino acids can be accomplished with strong acids such as trifluoroacetic acid in dichloromethane, or with HCl in methanol. [ 2 ] [ 3 ] [ 4 ] A complication may be the tendency of the t -butyl cation intermediate to alkylate other nucleophiles; scavengers such as anisole or thioanisole may be used.