Solubility of iron(II) carbonate at temperatures between 30 and 80 degrees

Measurements were made of the forward rate-constant (k(f)) for the dissolution of FeCO(3) at 10 degrees temperature intervals between 30 and 80 degrees and in buffered solutions at pH 4, 5, 6 and 7. The solubility product (K(sp)) of FeCO(3) was measured at the same six temperatures. The forward rate-constant is related to temperature (T, degrees C) and pH by pk(f) = pH - 0.0350T + 0.695. The solubility product of FeCO(3) is related to temperature by pK(sp) = 0.0314T + 10.20. Kinetic data indicate that, under the conditions of the study, the rate-determining step of the dissolution reaction is FeCO(3)(s) + H(+) --> Fe(2+) + HCO(-)(3).