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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Niel Plummer</dc:contributor>
  <dc:contributor>Vivian B. Parker</dc:contributor>
  <dc:creator>Eurybiades Busenberg</dc:creator>
  <dc:date>1984</dc:date>
  <dc:description>&lt;p id=""&gt;Seventy new measurements (Sr&lt;sub&gt;T&lt;/sub&gt;-P&lt;sub&gt;co2&lt;/sub&gt;&amp;nbsp;of the solubility of strontianite were used to evaluate the equilibrium constant for the reaction&amp;nbsp;&lt;i&gt;SrCO&lt;/i&gt;&lt;sub&gt;3&lt;/sub&gt;(&lt;i&gt;cr&lt;/i&gt;) =&amp;nbsp;&lt;i&gt;Sr&lt;/i&gt;&lt;sup&gt;2+&lt;/sup&gt;(&lt;i&gt;aq&lt;/i&gt;) +&amp;nbsp;&lt;i&gt;CO&lt;/i&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(&lt;i&gt;aq&lt;/i&gt;) between 2 and 91 &amp;deg;C. The temperature dependence of the equilibrium constant is given by the expression Log&amp;nbsp;&lt;i&gt;K&lt;/i&gt;&amp;nbsp;= 155.0305 &amp;minus; 7239.594/&lt;i&gt;T&lt;/i&gt;&amp;nbsp;&amp;minus; 56.58638 log&amp;nbsp;&lt;i&gt;T&lt;/i&gt;&amp;nbsp;where&amp;nbsp;&lt;i&gt;T&lt;/i&gt;&amp;nbsp;is in degrees Kelvin. The log&amp;nbsp;&lt;i&gt;K&lt;/i&gt;&amp;nbsp;of strontianite, the Gibbs energy, enthalpy and entropy of the reaction at 25&amp;deg;C are &amp;minus;9.271 &amp;plusmn; 0.020, 52.919 &amp;plusmn; 0.08&amp;nbsp;&lt;i&gt;kJ&lt;/i&gt;&amp;nbsp;&amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, &amp;minus;1.67 &amp;plusmn; 1.30&amp;nbsp;&lt;i&gt;kJ&lt;/i&gt;&amp;nbsp;&amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, and &amp;minus;183.1 &amp;plusmn; 4.0&amp;nbsp;&lt;i&gt;J&lt;/i&gt;&amp;nbsp;&amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;nbsp;&amp;middot;&amp;nbsp;&lt;i&gt;K&lt;/i&gt;&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, respectively. The equilibrium constants are consistent with an aqueous model that includes the ion pairs SrHCO&lt;sup&gt;+&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(aq) and SrCO&lt;sup&gt;0&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(aq) which were evaluated by potentiometric methods between 5 and 80&amp;deg;C. The equilibrium constant for the association reaction&amp;nbsp;&lt;i&gt;Sr&lt;/i&gt;&lt;sup&gt;2+&lt;/sup&gt;(&lt;i&gt;aq&lt;/i&gt;) +&amp;nbsp;&lt;i&gt;HCO&lt;/i&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(&lt;i&gt;aq&lt;/i&gt;) =&lt;i&gt;SrHCO&lt;/i&gt;&lt;sup&gt;+&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;i&gt;aq&lt;/i&gt;) is given by the expression Log&amp;nbsp;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;SrHCO&lt;/i&gt;&lt;sup&gt;+&lt;/sup&gt;3&lt;/sub&gt;&amp;nbsp;= &amp;minus;3.248 + 0.014867&lt;i&gt;T&lt;/i&gt;. The log of the association constant, the Gibbs energy, enthalpy and entropy of the reaction at 25&amp;deg;C are 1.18, &amp;minus;6.76 kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, 25.30 kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, and 107.5 J &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;nbsp;&amp;middot; K&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, respectively. The equilibrium constant for the association reaction&amp;nbsp;&lt;i&gt;Sr&lt;/i&gt;&lt;sup&gt;2+&lt;/sup&gt;(&lt;i&gt;aq&lt;/i&gt;) +&amp;nbsp;&lt;i&gt;CO&lt;/i&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(&lt;i&gt;aq&lt;/i&gt;) =&amp;nbsp;&lt;i&gt;SrCO&lt;/i&gt;&lt;sup&gt;0&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;i&gt;aq&lt;/i&gt;) is given by the expression Log&amp;nbsp;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;SrCO&lt;/i&gt;&lt;sup&gt;0&lt;/sup&gt;3&lt;/sub&gt;&amp;nbsp;= &amp;minus;1.019 + 0.012826&lt;i&gt;T&lt;/i&gt;. The log of the association constant, the Gibbs energy, enthalpy, and entropy of the reaction at 25&amp;deg;C are 2.81, &amp;minus;16.01 kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;,21.83 kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, and 126.9 J &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;nbsp;&amp;middot; K&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, respectively. These results lead to reliable calculation of the aqueous speciation and solubility of strontianite in the system SrCO&lt;sub&gt;3&lt;/sub&gt;-CO&lt;sub&gt;2&lt;/sub&gt;-H&lt;sub&gt;2&lt;/sub&gt;O from 0 to more than 90&amp;deg;C. Literature data on the solubility of strontianite have been evaluated and compared with these results.&lt;/p&gt;
&lt;p id=""&gt;Our new data for strontianite have been used in an evaluation of the thermodynamic properties of Sr&lt;sup&gt;2+&lt;/sup&gt;(aq), SrCO&lt;sub&gt;3&lt;/sub&gt;(cr) and related compounds. The following values are recommended for the standard enthalpy (kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;), Gibbs energy (kJ &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;), and entropy (J &amp;middot; mol&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;nbsp;&amp;middot; K&lt;sup&gt;&amp;minus;1&lt;/sup&gt;), respectively, of Sr&lt;sup&gt;2+&lt;/sup&gt;aq): &amp;minus;550.90 &amp;plusmn; 0.50, &amp;minus;563.83 &amp;plusmn; 0.8 and &amp;minus;31.50 &amp;plusmn; 2.0, and for SrCO&lt;sub&gt;3&lt;/sub&gt;(cr): &amp;minus;1225.77 &amp;plusmn; 1.1, &amp;minus;1144.73 &amp;plusmn; 1.0 and 97.2.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(84)90383-1</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>The solubility of strontianite (SrCO&lt;sub&gt;3&lt;/sub&gt;) in CO&lt;sub&gt;2&lt;/sub&gt;-H&lt;sub&gt;2&lt;/sub&gt;O solutions between 2 and 91°C, the association constants of SrHCO&lt;sup&gt;+&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(aq) and SrCO&lt;sup&gt;0&lt;/sup&gt;&lt;sub&gt;3&lt;/sub&gt;(aq) between 5 and 80°C, and an evaluation of the thermodynamic properties of Sr&lt;sup&gt;2+&lt;/sup&gt;(aq) and SrCO&lt;sub&gt;3&lt;/sub&gt;(cr) at 25°C and 1 atm total pressure</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>