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Chemical garden

January 01, 1970

A chemical garden is a set of complex biological-looking structures created by mixing inorganic chemicals. This experiment in chemistry is usually performed by adding metal salts, such as copper sulfate or cobalt(II) chloride, to an aqueous solution of sodium silicate (otherwise known as waterglass). This results in the growth of plant-like forms in minutes to hours.[1][2][3][4]

Comparison of chemical gardens grown by NASA scientists on the International Space Station (left) and on the ground (right)
A chemical garden while growing
Cobalt(II) chloride
A chemical garden

The chemical garden was first observed and described by Johann Rudolf Glauber in 1646.[5] In its original form, the chemical garden involved the introduction of ferrous chloride (FeCl2) crystals into a solution of potassium silicate (K2SiO3).

Process edit

The chemical garden relies on most transition metal silicates being insoluble in water and colored.

When a metal salt, such as cobalt chloride, is added to a sodium silicate solution, it will start to dissolve. It will then form insoluble cobalt silicate by a double displacement reaction. This cobalt silicate is a semipermeable membrane. Because the ionic strength of the cobalt solution inside the membrane is higher than the sodium silicate solution's, which forms the bulk of the tank contents, osmotic effects will increase the pressure within the membrane. This will cause the membrane to tear, forming a hole. The cobalt cations will react with the silicate anions at this tear to form a new solid. In this way, growths will form in the tanks; they will be colored (according to the metal cation) and may look like plant-like structures.

The usual upward direction of growth depends on the density of the fluid inside the semi-permeable membrane of the "plant" being lower than that of the surrounding waterglass solution. If one uses a metal salt that produces a very dense fluid inside the membrane, the growth is downward. For example, a green solution of trivalent chromium sulfate or chloride refuses to crystallize without slowly changing into the violet form[clarification needed], even if boiled until it concentrates into a tarry mass. That tar, if suspended in the waterglass solution, forms downward twig-like growths. This is because all the fluid inside the membrane is too dense to float and thereby exerts a downward force. The concentration of sodium silicate becomes important in growth rate.

After the growth has ceased, the sodium silicate solution can be removed by a continuous addition of water at a very slow rate. This prolongs the life of the garden.[6]

In one specific experimental variation, researchers produced the chemical garden with a single growth "tube".[7]

Common salts used edit

Common salts used in a chemical garden include:[8]

Practical uses edit

While at first the chemical garden may appear to be primarily a toy, some serious work has been done on the subject.[3] For instance, this chemistry is related to the setting of Portland cement, the formation of hydrothermal vents, and during the corrosion of steel surfaces on which insoluble tubes can be formed.

The nature of the growth of the insoluble silicate tubes formed within chemical gardens is also useful in understanding classes of related behavior seen in fluids separated by membranes. In various ways, the growth of the silicate tubes resembles the growth of spikes or blobs of ice extruded above the freezing surface of still water,[9] the patterns of growth of gum drying as it drips from wounds in trees such as Eucalyptus, and the way molten wax forms twig-like growths, either dripping from a candle, or floating up through cool water.[citation needed]

Paleontology edit

If the conditions are good, chemical gardens can also occur in nature. There is evidence from paleontology, that such chemical gardens may fossilize. Such pseudofossils can be very difficult to distinguish from fossilized organisms. Indeed, some of the earliest purported fossils of life might be fossilized chemical gardens.[10]

Mixing iron-rich particles with alkaline liquids containing the chemicals silicate or carbonate have created biological-looking structures. Such structures may appear to be biological and/or fossils.[11][12][13] According to researchers, "Chemical reactions like these have been studied for hundreds of years but they had not previously been shown to mimic these tiny iron-rich structures inside rocks. These results call for a re-examination of many ancient real-world examples to see if they are more likely to be fossils or non-biological mineral deposits."[11][12]

One use of the study of chemical gardening is to be better able to distinguish biological structures, including fossils, from non-biological structures on the planet Mars.[11][12]

See also edit

References edit

  1. ^ Barge, Laura M.; et al. (26 August 2015). "From Chemical Gardens to Chemobrionics". Chemical Reviews. 115 (16): 8652–8703. doi:10.1021/acs.chemrev.5b00014. hdl:20.500.11824/172. ISSN 0009-2665. PMID 26176351.
  2. ^ Balköse, D.; Özkan, F.; Köktürk, U.; Ulutan, S.; Ülkü, S.; Nişli, G. (2002). "Characterization of Hollow Chemical Garden Fibers from Metal Salts and Water Glass" (PDF). Journal of Sol-Gel Science and Technology. 23 (3): 253. doi:10.1023/A:1013931116107. hdl:11147/4652. S2CID 54973427.
  3. ^ a b Cartwright, J; García-Ruiz, Juan Manuel; Novella, María Luisa; Otálora, Fermín (2002). "Formation of Chemical Gardens". Journal of Colloid and Interface Science. 256 (2): 351. Bibcode:2002JCIS..256..351C. CiteSeerX 10.1.1.7.7604. doi:10.1006/jcis.2002.8620.
  4. ^ Thouvenel-Romans, S; Steinbock, O (April 2003). (PDF). Journal of the American Chemical Society. 125 (14): 4338–41. doi:10.1021/ja0298343. ISSN 0002-7863. PMID 12670257. Archived from the original (PDF) on 11 August 2017. Retrieved 23 May 2009.
  5. ^ Glauber, Johann Rudolf (1646). "Wie man in diesem Liquore von allen Metallen in wenig Stunden Bäume mit Farben soll wachsen machen." [How one shall make grow—in this solution, from all metals, in a few hours—trees with color]. Furni Novi Philosophici (German-language 1661 ed.). Amsterdam: Johan Jansson. pp. 186–189.
  6. ^ Helmenstine, Anne Marie (16 March 2019). "Magic Rocks". thoughtco.com. Archived from the original on 16 May 2020. Retrieved 16 May 2020.
  7. ^ Glaab, F.; Kellermeier, M.; Kunz, W.; Morallon, E.; García-Ruiz, J. M. (2012). "Formation and Evolution of Chemical Gradients and Potential Differences Across Self-Assembling Inorganic Membranes". Angewandte Chemie International Edition. 51 (18): 4317–4321. doi:10.1002/anie.201107754. PMID 22431259.
  8. ^ Pimentel C, Zheng M, Cartwright JH, Sainz-Díaz CI (15 February 2023). "Chemobrionics Database: Categorisation of Chemical Gardens According to the Nature of the Anion, Cation and Experimental Procedure". ChemSystemsChem. John Wiley & Sons, Ltd: e202300002. doi:10.1002/syst.202300002. hdl:10481/81351. S2CID 256932493. Retrieved 16 March 2023.
  9. ^ Carter, James R. . Illinois State University. Archived from the original on 26 November 2017. Retrieved 14 November 2020.
  10. ^ McMahon, Sean (2020). "Earth's earliest and deepest purported fossils may be iron-mineralized chemical gardens". Proceedings of the Royal Society B: Biological Sciences. 286 (1916). doi:10.1098/rspb.2019.2410. PMC 6939263. PMID 31771469.
  11. ^ a b c University of Edinburgh (27 November 2019). "Solving fossil mystery could aid quest for ancient life on Mars". EurekAlert!. Retrieved 27 November 2019.
  12. ^ a b c McMahon, Sean (27 November 2019). "Earth's earliest and deepest purported fossils may be iron-mineralized chemical gardens". Proceedings of the Royal Society B. 286 (1916). doi:10.1098/rspb.2019.2410. PMC 6939263. PMID 31771469.
  13. ^ Steinbock, Oliver; et al. (1 March 2019). "The fertile physics of chemical gardens". Physics Today. 69 (3): 44. doi:10.1063/PT.3.3108.

External links edit

 
Wikimedia Commons has media related to Silicate garden.

January 01, 1970
chemical, garden, chemical, garden, complex, biological, looking, structures, created, mixing, inorganic, chemicals, this, experiment, chemistry, usually, performed, adding, metal, salts, such, copper, sulfate, cobalt, chloride, aqueous, solution, sodium, sili. A chemical garden is a set of complex biological looking structures created by mixing inorganic chemicals This experiment in chemistry is usually performed by adding metal salts such as copper sulfate or cobalt II chloride to an aqueous solution of sodium silicate otherwise known as waterglass This results in the growth of plant like forms in minutes to hours 1 2 3 4 Comparison of chemical gardens grown by NASA scientists on the International Space Station left and on the ground right source source source source A chemical garden while growing Cobalt II chloride A chemical garden The chemical garden was first observed and described by Johann Rudolf Glauber in 1646 5 In its original form the chemical garden involved the introduction of ferrous chloride FeCl2 crystals into a solution of potassium silicate K2SiO3 Contents 1 Process 2 Common salts used 3 Practical uses 4 Paleontology 5 See also 6 References 7 External linksProcess editThe chemical garden relies on most transition metal silicates being insoluble in water and colored When a metal salt such as cobalt chloride is added to a sodium silicate solution it will start to dissolve It will then form insoluble cobalt silicate by a double displacement reaction This cobalt silicate is a semipermeable membrane Because the ionic strength of the cobalt solution inside the membrane is higher than the sodium silicate solution s which forms the bulk of the tank contents osmotic effects will increase the pressure within the membrane This will cause the membrane to tear forming a hole The cobalt cations will react with the silicate anions at this tear to form a new solid In this way growths will form in the tanks they will be colored according to the metal cation and may look like plant like structures The usual upward direction of growth depends on the density of the fluid inside the semi permeable membrane of the plant being lower than that of the surrounding waterglass solution If one uses a metal salt that produces a very dense fluid inside the membrane the growth is downward For example a green solution of trivalent chromium sulfate or chloride refuses to crystallize without slowly changing into the violet form clarification needed even if boiled until it concentrates into a tarry mass That tar if suspended in the waterglass solution forms downward twig like growths This is because all the fluid inside the membrane is too dense to float and thereby exerts a downward force The concentration of sodium silicate becomes important in growth rate After the growth has ceased the sodium silicate solution can be removed by a continuous addition of water at a very slow rate This prolongs the life of the garden 6 In one specific experimental variation researchers produced the chemical garden with a single growth tube 7 Common salts used editCommon salts used in a chemical garden include 8 Aluminium potassium sulfate White Copper II sulfate Blue Chromium III chloride Green Nickel II sulfate Green Iron II sulfate Green Iron III chloride Orange Cobalt II chloride Purple Calcium chloride White Zinc sulfate WhitePractical uses editWhile at first the chemical garden may appear to be primarily a toy some serious work has been done on the subject 3 For instance this chemistry is related to the setting of Portland cement the formation of hydrothermal vents and during the corrosion of steel surfaces on which insoluble tubes can be formed The nature of the growth of the insoluble silicate tubes formed within chemical gardens is also useful in understanding classes of related behavior seen in fluids separated by membranes In various ways the growth of the silicate tubes resembles the growth of spikes or blobs of ice extruded above the freezing surface of still water 9 the patterns of growth of gum drying as it drips from wounds in trees such as Eucalyptus and the way molten wax forms twig like growths either dripping from a candle or floating up through cool water citation needed Paleontology editIf the conditions are good chemical gardens can also occur in nature There is evidence from paleontology that such chemical gardens may fossilize Such pseudofossils can be very difficult to distinguish from fossilized organisms Indeed some of the earliest purported fossils of life might be fossilized chemical gardens 10 Mixing iron rich particles with alkaline liquids containing the chemicals silicate or carbonate have created biological looking structures Such structures may appear to be biological and or fossils 11 12 13 According to researchers Chemical reactions like these have been studied for hundreds of years but they had not previously been shown to mimic these tiny iron rich structures inside rocks These results call for a re examination of many ancient real world examples to see if they are more likely to be fossils or non biological mineral deposits 11 12 One use of the study of chemical gardening is to be better able to distinguish biological structures including fossils from non biological structures on the planet Mars 11 12 See also editMercury beating heart Barking dog reactionReferences edit Barge Laura M et al 26 August 2015 From Chemical Gardens to Chemobrionics Chemical Reviews 115 16 8652 8703 doi 10 1021 acs chemrev 5b00014 hdl 20 500 11824 172 ISSN 0009 2665 PMID 26176351 Balkose D Ozkan F Kokturk U Ulutan S Ulku S Nisli G 2002 Characterization of Hollow Chemical Garden Fibers from Metal Salts and Water Glass PDF Journal of Sol Gel Science and Technology 23 3 253 doi 10 1023 A 1013931116107 hdl 11147 4652 S2CID 54973427 a b Cartwright J Garcia Ruiz Juan Manuel Novella Maria Luisa Otalora Fermin 2002 Formation of Chemical Gardens Journal of Colloid and Interface Science 256 2 351 Bibcode 2002JCIS 256 351C CiteSeerX 10 1 1 7 7604 doi 10 1006 jcis 2002 8620 Thouvenel Romans S Steinbock O April 2003 Oscillatory growth of silica tubes in chemical gardens PDF Journal of the American Chemical Society 125 14 4338 41 doi 10 1021 ja0298343 ISSN 0002 7863 PMID 12670257 Archived from the original PDF on 11 August 2017 Retrieved 23 May 2009 Glauber Johann Rudolf 1646 Wie man in diesem Liquore von allen Metallen in wenig Stunden Baume mit Farben soll wachsen machen How one shall make grow in this solution from all metals in a few hours trees with color Furni Novi Philosophici German language 1661 ed Amsterdam Johan Jansson pp 186 189 Helmenstine Anne Marie 16 March 2019 Magic Rocks thoughtco com Archived from the original on 16 May 2020 Retrieved 16 May 2020 Glaab F Kellermeier M Kunz W Morallon E Garcia Ruiz J M 2012 Formation and Evolution of Chemical Gradients and Potential Differences Across Self Assembling Inorganic Membranes Angewandte Chemie International Edition 51 18 4317 4321 doi 10 1002 anie 201107754 PMID 22431259 Pimentel C Zheng M Cartwright JH Sainz Diaz CI 15 February 2023 Chemobrionics Database Categorisation of Chemical Gardens According to the Nature of the Anion Cation and Experimental Procedure ChemSystemsChem John Wiley amp Sons Ltd e202300002 doi 10 1002 syst 202300002 hdl 10481 81351 S2CID 256932493 Retrieved 16 March 2023 Carter James R Ice Formations with Daily Diurnal Freeze Thaw Cycles Illinois State University Archived from the original on 26 November 2017 Retrieved 14 November 2020 McMahon Sean 2020 Earth s earliest and deepest purported fossils may be iron mineralized chemical gardens Proceedings of the Royal Society B Biological Sciences 286 1916 doi 10 1098 rspb 2019 2410 PMC 6939263 PMID 31771469 a b c University of Edinburgh 27 November 2019 Solving fossil mystery could aid quest for ancient life on Mars EurekAlert Retrieved 27 November 2019 a b c McMahon Sean 27 November 2019 Earth s earliest and deepest purported fossils may be iron mineralized chemical gardens Proceedings of the Royal Society B 286 1916 doi 10 1098 rspb 2019 2410 PMC 6939263 PMID 31771469 Steinbock Oliver et al 1 March 2019 The fertile physics of chemical gardens Physics Today 69 3 44 doi 10 1063 PT 3 3108 External links edit nbsp Wikimedia Commons has media related to Silicate garden Chemical Garden at The Periodic Table of Videos University of Nottingham Chemical Gardens Colloidal garden at http chemistry chemists com Chemobrionics COST Action linking European research groups to stimulate innovative and high impact interdisciplinary scientintific research on chemical gardens Chemobrionics Database Portals nbsp Biology nbsp Chemistry nbsp Minerals nbsp Physics Retrieved from https en wikipedia org w index php title Chemical garden amp oldid 1210613977, wikipedia, wiki, book, books, library,

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