Question

Which calcium compound is not appreciably more soluble in 0.1 M hydrochloric acid than it is in pure water?

(A) Limestone, CaCO3
(B) Slaked lime, Ca(OH)2
(C) Gypsum, CaSO4 • 2 H2O
(D) Hydroxyapatite, Ca5(OH)(PO4)3

Answer 1

Are you sure the choices are correct?

Explanation:

All of these species contain basic ligands, that should be protonated in acidic solution....i.e.

`CaCO_3(s) + 2HCl(aq) rarr CaCl_2(aq) + CO_2(g)uarr + H_2O(l)`

`"Hydroxyapatite"` should display the LEAST solubility...but we are flying blind as we gots no data. Would you post the answer you are given?