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The difference between successive pK a values is sufficiently large so that salts of either monohydrogen phosphate, HPO 2− 4 or dihydrogen phosphate, H 2 PO − 4, can be prepared from a solution of phosphoric acid by adjusting the pH to be mid-way between the respective pK a values.
The equilibrium is not complete because the acidity difference between guanidinium and water is not large. The approximate pK a values: 13.6 vs 15.7. Complete deprotonation should be done with extremely strong bases, such as lithium diisopropylamide. C(NH 2) + 3 Cl − + Li + N(C 3 H 7) − 2 → HNC(NH 2) 2 + HN(C 3 H 7) 2 + LiCl
Between the two buffer regions there is an end-point, or equivalence point, at about pH 3. This end-point is not sharp and is typical of a diprotic acid whose buffer regions overlap by a small amount: pK a2 − pK a1 is about three in this example. (If the difference in pK values were about two or less, the end-point would not be noticeable ...
Phillips et al. reported ∆H 0 at 25 °C of 760 cal/mol (3180 J/mol) and a linear dependence of pK a 0 on 1/T (Van 't Hoff equation). The positive ∆H 0 results in an increase in K a , and thus a decrease in p K a 0 with rising temperature, the change in pKa 0 being 166 × the change in (1/ T ), which around 25 °C results in a change in p K ...
It is also used as a strong reducing agent and in the production of synthetic fibres, organophosphorus pesticides, and the highly efficient water treatment agent ATMP. Ferrous materials, including steel, may be somewhat protected by promoting oxidation ("rust") and then converting the oxidation to a metalophosphate by using phosphoric acid and ...
Aluminium sulfate is a salt with the formula Al 2 (SO 4) 3.It is soluble in water and is mainly used as a coagulating agent (promoting particle collision by neutralizing charge) in the purification of drinking water [3] [4] and wastewater treatment plants, and also in paper manufacturing.
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH 3 (aq). Although the name ammonium hydroxide suggests a salt with the composition [NH + 4][OH −
If dissolved in pure water, the pH is halfway between these two pKa values. Purine is aromatic, having four tautomers each with a hydrogen bonded to a different one of the four nitrogen atoms. These are identified as 1-H, 3-H, 7-H, and 9-H (see image of numbered ring).