Alkalimetric
titration of phosphoric acid and phosphates
Authors
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J. C. W. Dijksman
o
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Cited by: 1 article
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Abstract
Many contradictory data are known concerning the
alkalimetric titration of phosphoric acid. The uncertainties, which have
received a solution in this investigation, concern:
·
1the
correct titration exponent in titration to mono or diphosphate;
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2the
correct composition of crystalline disodium phosphate which turned out to be
exactly Na2HPO4.
12H2O;
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3the
inflexion points in the titration curve were found to coincide with the
equivalence points.
Further a search was made for a suitable and accurate
method of carrying out an alkalimetric phosphate determination in phosphates
containing calcium, aluminium and iron, because the known methods are all
unreliable. A removal of the disturbing metallic ions with the aid of a cation
exchanger was found to be the solution. An attempt was made, but without
ultimate success, to exclude disturbing fluoride and silicofluoride.
The demands, which
must be made in alkalimetric titrations on the purity of distilled water, have
been sorted out and summarised.