Reaction #1960515

Reaction equation

octacalcium phosphate

calcium nitrate tetrahydrate

H3PO2

→

Calcium Phosphate

Conditions

Workup

1. 1
   workup.DISTILLATIONdistilled water
2. 2
   Otherto form a clear, colorless solution in a 250 ml Pyrex beaker on a hotplate/stirrer
3. 3
   Othereventually forming a homogeneous solution once the sample
4. 4
   TemperatureWarming of the solution above 25° C.
5. 5
   Othera vigorous exothermic reaction
6. 6
   Otherthe reaction was essentially complete leaving a moist, white, pasty solid

Procedure

An aqueous solution of 8.06 g 50 wt % H3PO2 reagent was combined with 6.00 g distilled water to form a clear, colorless solution in a 250 ml Pyrex beaker on a hotplate/stirrer. To this solution was added 19.23 g Ca(NO3)2.4H2O. The molar ratio of Ca/phosphate in this sample was 4/3 and the equivalent solids [as octacalcium phosphate, Ca8H2(PO4)6-5H2O] was 30.0 wt %. Endothermic dissolution of the calcium nitrate tetrahydrate proceeded under ambient conditions, eventually forming a homogeneous solution once the sample warmed to room temperature. Warming of the solution above 25° C. initiated a vigorous exothermic reaction as described in Example 1. After approximately three minutes, the reaction was essentially complete leaving a moist, white, pasty solid.

Source