Commonly used methods to prepare HAP mainly include hydrothermal method, precipitation method, solvothermal method, spontaneous combustion method, micro-emulsion method, ultrasonic synthesis method, bionic method and solid state reaction method, namely wet method and dry method.

HydroxyapatiteUnit cella = 9.41 Å, c = 6.88 Å; Z = 2IdentificationFormula mass502.31 g/molColorColorless, white, gray, yellow, yellowish green21 صفًا آخر

How many g of NH4H2PO4 are required to react

with 1 g of Ca(OH)2 to produce Ca10(PO4)6(OH)2 (Ca/P=1.667)

according to the equation

Eq 1: 10 Ca (OH)2 + 6 H3PO4 -> Ca10(PO4)6(OH)2 + 8 H2O

Well, first of all we need to have an equation that involves the reactant NH4H2PO4.

We could write it as a dissociation to form H3PO4 as follows

Eq 2: NH4H2PO4 + H2O NH4OH + H3PO4

If we add 6 NH4OH to each side of the original equation we get

Eq 3: 10 Ca (OH)2 + 6 H3PO4 + 6 NH4OH -> Ca10(PO4)6(OH)2 + 8 H2O + 6 NH4OH

We then replace the 6 H3PO4 + 6 NH4OH on the left with it's equivalent from Eq 2 to get

Eq 4: 10 Ca (OH)2 + 6 NH4H2PO4 + 6 H2O -> Ca10(PO4)6(OH)2 + 8 H2O + 6 NH4OH

Now subtract 6 H20 from each side to get

Eq 5: 10 Ca (OH)2 + 6 NH4H2PO4 -> Ca10(PO4)6(OH)2 + 2 H2O + 6 NH4OH

We could count up atoms of each element on the two sides

to see that they balance, for example 10 Ca, 6 N, 6 P, etc.

The gram-molar mass (molecular weight) of Ca(OH)2 is 74 g/mole.

and that of NH4H2PO4 is 115 g/mole

Thus one gram of Ca(OH)2 is 0.0135 moles of Ca(OH)2

This would react with 6/10 as many moles of NH4H2PO4

or 0.0081 moles of NH4H2PO4.

That times its gram-molar mass is 0,93 g of NH4H2PO4

required to react fully with 1 g of Ca (OH)2