<?xml version='1.0' encoding='utf-8'?>
<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>C. L. Christ</dc:contributor>
  <dc:creator>P. B. Hostetler</dc:creator>
  <dc:date>1968</dc:date>
  <dc:description>&lt;p&gt;Chrysotile dissolves congruently in water according to the reaction:&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Mg&lt;/i&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;i&gt;Si&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;i&gt;O&lt;/i&gt;&lt;sub&gt;6&lt;/sub&gt;(&lt;i&gt;OH&lt;/i&gt;)&lt;sub&gt;4&lt;i&gt;c&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;+ 5&lt;i&gt;H&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;i&gt;O&lt;/i&gt;&lt;sub&gt;&lt;i&gt;l&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 3&lt;i&gt;Mg&lt;/i&gt;&lt;sub&gt;&lt;i&gt;aq&lt;/i&gt;&lt;/sub&gt;&lt;sup&gt;2+&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;+ 6&lt;i&gt;OH&lt;/i&gt;&lt;sub&gt;&lt;i&gt;aq&lt;/i&gt;&lt;/sub&gt;&lt;sup&gt;−&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;+ 2&lt;i&gt;H&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;i&gt;SiO&lt;/i&gt;&lt;sub&gt;4&lt;i&gt;aq&lt;/i&gt;&lt;/sub&gt;. Experimental determination of the activity-product constant of chrysotile,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;chr&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= [&lt;i&gt;Mg&lt;/i&gt;&lt;sup&gt;2+&lt;/sup&gt;]&lt;sup&gt;3&lt;/sup&gt;[&lt;i&gt;OH&lt;/i&gt;&lt;sup&gt;−&lt;/sup&gt;]&lt;sup&gt;6&lt;/sup&gt;[&lt;i&gt;H&lt;/i&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;i&gt;SiO&lt;/i&gt;&lt;sub&gt;4&lt;i&gt;aq&lt;/i&gt;&lt;/sub&gt;]&lt;sup&gt;2&lt;/sup&gt;, at 90°C, yields the value of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;chr&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 10&lt;sup&gt;−49.2&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;± 10&lt;sup&gt;0.5&lt;/sup&gt;. A synthetic sample and a natural sample from New Idria, California, were used in the determination.&lt;/p&gt;&lt;p&gt;Values of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;chr&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;were calculated for temperatures ranging from 0°C to 200°C, using the thermochemical data of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="small-caps"&gt;King&lt;/span&gt;&lt;i&gt;et al&lt;/i&gt;. (1967) for chrysotile and antigorite, various solubility data for silica, and ionic partial molal heat capacities estimated by the method of criss and Cobble (1964a).&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;chr&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is 10&lt;sup&gt;−54.1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;at 0°C, rises to a maximum value of 10&lt;sup&gt;−48.5&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;at approximately 135°C, and is 10&lt;sup&gt;−49.1&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;at 200°C (all values for the three-phase system, chrysotile plus solution plus vapor). The calculated 90°C value is 10&lt;sup&gt;−49.1&lt;/sup&gt;, in excellent agreement with the experimental value; for 25°C, the calculated value is 10&lt;sup&gt;−50.8&lt;/sup&gt;.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-7037(68)90041-0</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Studies in the system MgO-SiO2-CO2-H2O(I): The activity-product constant of chrysotile</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>