Skip to main content

Advertisement

Tables 2 Analytical data and solubility determination of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1‒x)5(PO4)3OH] (25 °C and an initial pH of 2.00)

From: Characterization, dissolution and solubility of the hydroxypyromorphite–hydroxyapatite solid solution [(PbxCa1−x)5(PO4)3OH] at 25 °C and pH 2–9

Sample Dissolution time (h) pH Concentration (mmol/L) logK sp Average logK sp ΔG f o (kJ/mol) Average ΔG f o (kJ/mol)
Pb Ca P
(Pb0.00Ca1.00)5(PO4)3OH 5040 4.75 0.00000 8.03 5.57 −58.46 −58.38 −6315.06 −6314.63
5760 4.77 0.00000 8.03 5.59 −58.31   −6314.21  
7200 4.76 0.00000 8.04 5.58 −58.38   −6314.61  
(Pb0.10Ca0.90)5(PO4)3OH 5040 4.55 0.00099 7.12 3.91 −62.39 −62.39 −6128.29 −6128.28
5760 4.54 0.00111 7.14 3.95 −62.41   −6128.42  
7200 4.55 0.00106 7.13 3.93 −62.36   −6128.12  
(Pb0.20Ca0.80)5(PO4)3OH 5040 4.46 0.00153 6.85 3.33 −64.99 −65.19 −5850.90 −5852.04
5760 4.39 0.00172 6.85 3.36 −65.42   −5853.34  
7200 4.44 0.00153 6.67 3.32 −65.16   −5851.87  
(Pb0.30Ca0.70)5(PO4)3OH 5040 4.36 0.00149 6.61 3.30 −67.59 −67.43 −5601.14 −5600.22
5760 4.39 0.00171 6.62 3.32 −67.27   −5599.35  
7200 4.37 0.00170 6.60 3.31 −67.42   −5600.17  
(Pb0.41Ca0.59)5(PO4)3OH 5040 4.45 0.00152 6.60 2.98 −69.07 −69.18 −5318.58 −5319.18
5760 4.43 0.00151 6.60 3.02 −69.19   −5319.28  
7200 4.42 0.00152 6.61 3.00 −69.27   −5319.69  
(Pb0.51Ca0.49)5(PO4)3OH 5040 4.43 0.00211 6.07 1.79 −71.35 −71.42 −5039.35 −5039.76
5760 4.42 0.00215 6.07 1.79 −71.40   −5039.60  
7200 4.40 0.00215 6.07 1.81 −71.52   −5040.33  
(Pb0.61Ca0.39)5(PO4)3OH 5040 4.32 0.00386 5.45 1.01 −73.84 −73.86 −4816.62 −4816.77
5760 4.34 0.00401 5.39 1.01 −73.64   −4815.53  
7200 4.28 0.00391 5.38 1.00 −74.10   −4818.15  
(Pb0.69Ca0.31)5(PO4)3OH 5040 4.30 0.00224 6.18 2.24 −75.01 −74.94 −4528.61 −4528.24
5760 4.33 0.00230 6.17 2.28 −74.73   −4527.06  
7200 4.28 0.00231 6.16 2.26 −75.08   −4529.04  
(Pb0.80Ca0.20)5(PO4)3OH 5040 4.12 0.00495 5.85 1.38 −77.40 −77.52 −4334.29 −4334.94
5760 4.11 0.00468 5.89 1.40 −77.55   −4335.13  
7200 4.09 0.00487 5.85 1.42 −77.59   −4335.39  
(Pb0.89Ca0.11)5(PO4)3OH 5040 3.41 0.11486 5.11 0.101 −81.11 −81.16 −4061.97 −4062.27
5760 3.35 0.11197 5.00 0.107 −81.49   −4064.16  
7200 3.36 0.13127 5.06 0.128 −80.88   −4060.67  
(Pb1.00Ca0.00)5(PO4)3OH 5040 2.63 3.75579 0.00 0.049 −80.96 −80.77 −3797.78 −3796.71
5760 2.67 3.64382 0.00 0.046 −80.79   −3796.79  
7200 2.68 3.70270 0.00 0.050 −80.57   −3795.55