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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: malusdb on June 15, 2020, 01:30:42 PM

Title: Precipitation of Monocalcium Phosphate
Post by: malusdb on June 15, 2020, 01:30:42 PM
Hello guys, i have an aqueous solution with Phosphate ions dissolved in it. If I add some Calcium salt, is there any way to precipitate Monocalcium Phosphate Ca(H2PO4)2 (to use as a fertilizer) rather than dicalcium phosphate or tricalcium phosphate ?

Thank you for the answers
Title: Re: Precipitation of Monocalcium Phosphate
Post by: chenbeier on June 15, 2020, 01:50:17 PM
You need phosphoric acid. Only from phosphate no way, the pH is neutral to alkaline. You need at least pH 2.
Title: Re: Precipitation of Monocalcium Phosphate
Post by: AWK on June 15, 2020, 02:42:35 PM
You need at least pH 2.
Rather a pH about 4.6.

What phosphate?
What is its concentration?
Compare the solubilities of your phosphate and Ca(H2PO4)2