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Scientific Skills. Gold. Gold. Shaun Lynn. J9106574. Occurrence & Extraction of Gold. Gold has an abundance of 4ppb of the Earth’s crust. Also found alloyed to other metals such as silver. Occurrence & Extraction of Gold. Nuggets. Grains. Microscopic. 2/3 world’s output .
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Scientific Skills Gold Gold Shaun Lynn J9106574
Occurrence & Extraction of Gold Gold has an abundance of 4ppb of the Earth’s crust Also found alloyed to other metals such as silver
Occurrence & Extraction of Gold Nuggets Grains Microscopic 2/3 world’s output .
Purification of Gold Smelting Cyanidation 4Au + 8NaCN +O2 +H2O 4[NaAu(CN)2] +4H2O
Reaction With Air & Water • Chemically unreactive • Does not react with air or with water Electron configuration is [Xe] 4f14 5d10 6s1 D orbital is saturated chemical unreactivity Crystal lattice structure is face centred cubic • Surface structure with limited freedom for bonding • Good for adsorption
Reaction With Acids Also unaffected by acids and bases Except: Aqua Regia (3:1 mixture of hydrochloric & nitric acid)
Reaction With Acids • Gold + Aqua Regia • This could be taken one step further to make chloroauric acid (liquid gold) Au (s) + 3 NO3-(aq) + 6 H+(aq) → Au3+(aq) + 3 NO2(g) + 3 H2O (l) Au3+(aq) + 4 Cl-(aq) → AuCl4-(aq)
Oxidation States • Gold has an oxidation state of +1 and +3 • However, it has the ability to reach a maximum oxidation number of +5 Such as Gold(v)pentaflouride!
Oxidation States • In an atmosphere of oxygen and fluorine, at 400°C at 8 atmospheres: • This will decompose at 180°C : 2 Au + 2 O2 + 6 F2 → 2 O2AuF6 2 golddioxyflouridesalt O2AuF6 → Au2F10 + 2 O2 + F2 Octahedral with Bi dentate fluoride bonds Gold(v) pentafluoride
Uses • Catalyst • Heterogeneous • Catalytic Converter • Adsorbs O2 and CO and allow CO2 to form.
Uses • As a catalyst: • Remove bad smells and toxins from the atmosphere • Glucose to Gluconic acid • Vinyl acetate monomers • In medicine: • Used to treat arthritis since 1929 • Prostate cancer treatment • Also: • Fine Jewellery • Currency is dependent upon gold
Interesting Compound! • Gold also has an oxidation state of -1 to form an Au-1 anion • This enables gold to react with metals with an oxidation state of +1, to form ionic compounds with non metalic properties. E.g. • CsAuCesiumAuride has a low melting point of 480°C classified as a semi conductor
References • Chloroauric Acid (Liquid gold) : Molecule of the Day. (2010, March 01). Retrieved march 01, 2010, from Science Bloggs: http://scienceblogs.com/moleculeoftheday/2007/08/chloroauric_acid_liquid_gold.php • Nobel Foundation. (2010, March 01). The Nobel Prize Medals and the Medal for the Prize in Economics. Retrieved March 01, 2010, from nobelprize.org: http://nobelprize.org/nobel_prizes/medals/ • Unknown. (2010, February 26). Gold element facts. Retrieved February 26, 2019, from Chemicool: http://www.chemicool.com/elements/gold.html • Unknown. (2010, February 2010). Gold Elements Facts. Retrieved february 28, 2010, from Chemicool: http://www.chemicool.com/elements/gold.html • Walker, J. (2010, march 08). What Gives Gold that Mellow Glow? Retrieved March 08, 2010, from Fourmilab Switzerland: http://www.fourmilab.ch/documents/golden_glow/ • Winter, M. (2010, February 28). Table of the Elements | Gold | chemical reaction data. Retrieved February 28, 2010, from WebElements : http://www.webelements.com/gold/chemistry.html • Housecroft, C. E. (2006). Chemistry An introduction to Organic, Inorganic and Physical Chemistry (Third Edition ed.). harlow, Essex, England: Pearson Education Limited. • World Gold Council. (n.d.). Properties. Retrieved march 07, 2010, from World Gold Council: http://www.utilisegold.com/uses_applications/properties_of_gold/ • World Gold Council. (n.d.). Uses and applications. Retrieved march 07, 2010, from World Gold Council: http://www.utilisegold.com/uses_applications/properties_of_gold/