{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/80120"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/80120","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Rates of reaction of covellite and blaubleibender covellite with ferric iron at ph 2.0","abstract":"The rates of reaction of pulverized samples (100-200 mesh) of blaubleibender covellite and covellite with 10⁻³ m ferric iron in a pH 2 solution were determined at 25, 35, and 50°C. Ferrous and cupric ion concentrations of the run solutions suggest that parallel reactions oxidized the sulfur to either elemental sulfur or to sulfate. The reaction that produces elemental sulfur is by far the fastest. The disappearance of ferric iron follows a first-order rate law which is a combination of the two first-order reactions: -dm<sub>Fe</sub>3+/dt = (k₁ + k₂) (A/M) m<sub>Fe</sub>3+ where m<sub>Fe</sub>3+ is the molal concentration of uncomplexed ferric iron, k₁ and k₂ are the rate constants and A/M is the ratio of the surface area of the reacting solid to the mass of the solution. At 25°C the measured rate constants are 7.14 x 10⁻⁵ ± 1% sec⁻¹ for blaubleibender covellite and 9.4 x 10⁻⁴ ± 1% sec⁻¹ for covellite indicating that blaubleibender covellite reacts almost an order of magnitude faster than stoichiometric covellite under these conditions. However, the activation energies for these reactions, over the temperature interval 25 to 50°C, are the same, within the range of the reported error: 51.8 ± 6.2 kJ mol⁻¹ for blaubleibender covellite and 58.29 ± -13. 7 kJ mol⁻¹ for covellite. This suggests that the rate limiting step for both reactions is the same. The relatively high activation energies indicate surface reactions control the rate of oxidation at these temperatures.","abstract_html":"The rates of reaction of pulverized samples (100-200 mesh) of blaubleibender covellite and covellite with 10⁻³ m ferric iron in a pH 2 solution were determined at 25, 35, and 50°C. Ferrous and cupric ion concentrations of the run solutions suggest that parallel reactions oxidized the sulfur to either elemental sulfur or to sulfate. The reaction that produces elemental sulfur is by far the fastest. The disappearance of ferric iron follows a first-order rate law which is a combination of the two first-order reactions: -dm&lt;sub&gt;Fe&lt;/sub&gt;3+/dt = (k₁ + k₂) (A/M) m&lt;sub&gt;Fe&lt;/sub&gt;3+ where m&lt;sub&gt;Fe&lt;/sub&gt;3+ is the molal concentration of uncomplexed ferric iron, k₁ and k₂ are the rate constants and A/M is the ratio of the surface area of the reacting solid to the mass of the solution. At 25°C the measured rate constants are 7.14 x 10⁻⁵ ± 1% sec⁻¹ for blaubleibender covellite and 9.4 x 10⁻⁴ ± 1% sec⁻¹ for covellite indicating that blaubleibender covellite reacts almost an order of magnitude faster than stoichiometric covellite under these conditions. However, the activation energies for these reactions, over the temperature interval 25 to 50°C, are the same, within the range of the reported error: 51.8 ± 6.2 kJ mol⁻¹ for blaubleibender covellite and 58.29 ± -13. 7 kJ mol⁻¹ for covellite. This suggests that the rate limiting step for both reactions is the same. The relatively high activation energies indicate surface reactions control the rate of oxidation at these temperatures.","abstract_has_math":false,"creators":["Walsh, Carol Ann"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geology","degree_department":"Geology","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1984,"date_issued":"1984","date_published":"1984","updated_at":"2026-07-22T22:19:24Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/80120","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Geology"]},{"key":"dc:creator","label":"Author","values":["Walsh, Carol Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-11-09T21:09:00Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-11-09T21:09:00Z"]},{"key":"dc:date.issued","label":"Date","values":["1984"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/80120"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The rates of reaction of pulverized samples (100-200 mesh) of blaubleibender covellite and covellite with 10⁻³ m ferric iron in a pH 2 solution were determined at 25, 35, and 50°C. Ferrous and cupric ion concentrations of the run solutions suggest that parallel reactions oxidized the sulfur to either elemental sulfur or to sulfate. The reaction that produces elemental sulfur is by far the fastest. The disappearance of ferric iron follows a first-order rate law which is a combination of the two first-order reactions: -dm<sub>Fe</sub>3+/dt = (k₁ + k₂) (A/M) m<sub>Fe</sub>3+ where m<sub>Fe</sub>3+ is the molal concentration of uncomplexed ferric iron, k₁ and k₂ are the rate constants and A/M is the ratio of the surface area of the reacting solid to the mass of the solution. At 25°C the measured rate constants are 7.14 x 10⁻⁵ ± 1% sec⁻¹ for blaubleibender covellite and 9.4 x 10⁻⁴ ± 1% sec⁻¹ for covellite indicating that blaubleibender covellite reacts almost an order of magnitude faster than stoichiometric covellite under these conditions. However, the activation energies for these reactions, over the temperature interval 25 to 50°C, are the same, within the range of the reported error: 51.8 ± 6.2 kJ mol⁻¹ for blaubleibender covellite and 58.29 ± -13. 7 kJ mol⁻¹ for covellite. This suggests that the rate limiting step for both reactions is the same. The relatively high activation energies indicate surface reactions control the rate of oxidation at these temperatures."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Rates of reaction of covellite and blaubleibender covellite with ferric iron at ph 2.0"]}]}],"canonical_facts":{"dc:contributor.department":["Geology"],"dc:creator":["Walsh, Carol Ann"],"dc:date.accessioned":["2017-11-09T21:09:00Z"],"dc:date.available":["2017-11-09T21:09:00Z"],"dc:date.issued":["1984"],"dc:description.abstract":["The rates of reaction of pulverized samples (100-200 mesh) of blaubleibender covellite and covellite with 10⁻³ m ferric iron in a pH 2 solution were determined at 25, 35, and 50°C. Ferrous and cupric ion concentrations of the run solutions suggest that parallel reactions oxidized the sulfur to either elemental sulfur or to sulfate. The reaction that produces elemental sulfur is by far the fastest. The disappearance of ferric iron follows a first-order rate law which is a combination of the two first-order reactions: -dm<sub>Fe</sub>3+/dt = (k₁ + k₂) (A/M) m<sub>Fe</sub>3+ where m<sub>Fe</sub>3+ is the molal concentration of uncomplexed ferric iron, k₁ and k₂ are the rate constants and A/M is the ratio of the surface area of the reacting solid to the mass of the solution. At 25°C the measured rate constants are 7.14 x 10⁻⁵ ± 1% sec⁻¹ for blaubleibender covellite and 9.4 x 10⁻⁴ ± 1% sec⁻¹ for covellite indicating that blaubleibender covellite reacts almost an order of magnitude faster than stoichiometric covellite under these conditions. However, the activation energies for these reactions, over the temperature interval 25 to 50°C, are the same, within the range of the reported error: 51.8 ± 6.2 kJ mol⁻¹ for blaubleibender covellite and 58.29 ± -13. 7 kJ mol⁻¹ for covellite. This suggests that the rate limiting step for both reactions is the same. The relatively high activation energies indicate surface reactions control the rate of oxidation at these temperatures."],"dc:description.degree":["Master of Science"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/80120"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Rates of reaction of covellite and blaubleibender covellite with ferric iron at ph 2.0"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:24Z"}