Dissolution Enthalpies of Magnesian Calcites
  • 【DOI】

    10.1023/A:1009684214945

  • 【摘要】

    A series of synthetic and biogenicmagnesian calcites was dissolved in weak acetic acidsolutions to measure the enthalpies of dissolution at25°C. For the synthetic phases, heat releasedwas 33.5 kJ/... 展开>>A series of synthetic and biogenicmagnesian calcites was dissolved in weak acetic acidsolutions to measure the enthalpies of dissolution at25°C. For the synthetic phases, heat releasedwas 33.5 kJ/mol for calcite, decreasing to 33 kJ/molfor a phase of 2 mol % MgCO3, and increasing to35 kJ/mol for a phase of 15 mol %. Values of excessenthalpies, DeltaHxs, calculated using calciteand magnesite end-members, average about -1 kJ/mol forthe synthetic phases. Total entropies of solidsolution formation, DeltaSSS, also werecalculated using available data on Gibbs free energiesof formation and these excess enthalpies. Values ofDeltaSSS range from -2 J/(mol-K) at 2 mol % to-5 J/(mol-K) at 15 mol % MgCO3. These negativevalues of 收起<<

  • 【作者】

  • 【刊期】

    Aquatic Geochemistry 1998年3-4期

  • 【语种】

    eng