[Jenna]

What is the reaction for

Potassium antimonyl tartrate + water            ? What does it produce, and then how can I calculate the concentration of the phosphate ion?

it is a 250 mL solution with .285 g of the KH2PO4

thanks

[Borek]

How is the 'potassium antimonyl tartrate' related to phosphate?

[chiralic]

How is the 'potassium antimonyl tartrate' related to phosphate?

Borek, this compound is one of the "ingredients" of ascorbic acid method (colorimetric technique) for to determinate REACTIVE PHOSPHATE in water and/or soil. Ammonium molybdate + potassium antimonyl tartrate in acid media react with Phosphorus and develop a blue colour (formation of colored 12-molybdophosphoric acid complex)

To Jenna:
Potassium antimonyl tartrate no react with water, react together to Ammonium molybdate in acid media WITH phosphorus (as phosphate) present in water. You need prepare a set of standards solutions of KH2PO4 using ASCORBIC ACID METHOD, them prepare a graphic Absorbance vs Concentration of PO4(-3) and you get the Concentration of Phosphate Ion. You must use water to prepare your solutions and standards FREE OF PHOSPHATES!!!!

See theses references:
- Murphy, J., and J. P. Riley. (1962) A modified single solution method for the determination of
  phosphate in natural waters. Anal. Chim. Acta 27: 31-36.

- Parsons, T.R., Maita, Y., Lalli, C.M.,  1984.  A manual of chemical and biological methods for seawater
  analysis.  Pergamon Press, New York.

Regards,

Chiralic