Difference between pages "Carat" and "Silver cyanide"

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[[File:2006.47-SC176532.jpg|thumb|Amethyst ring with 18kt gold<br>MFA# 2006.47]]
 
 
== Description ==
 
== Description ==
  
1) A unit of weight for gemstones. One carat is 200 milligrams. Carat was used in the middle ages by alchemists.
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White or gray, granular powder that darkens on exposure to light. Silver cyanide is used primarily for silver plating. Some chemical tarnish removal methods use dilute cyanide solutions for dipping followed by a water rinse. Cyanide solutions will react with silver to produce silver cyanide residues which are highly toxic.
  
2) (usually spelled karat) A unit of measure for the purity of gold.  Pure gold is 24 karat or 1000 fine.  A gold alloy that contains 75% gold is 18 karat or 750 fine.
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== Risks ==
  
== Synonyms and Related Terms ==
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* Highly toxic by ingestion, inhalation or skin absorption.
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* ThermoFisher: [https://www.fishersci.com/store/msds?partNumber=AC180230100&productDescription=SILVER+CYANIDE%2C+99%25+10GR&vendorId=VN00032119&countryCode=US&language=en SDS]
  
karat; Karat (Deut.); carat (Fr.); fine
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==Physical and Chemical Properties==
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Soluble in solutions of ammonium hydroxide, nitric acid, potassium cyanide, potassium ferricyanide and sodium thiosulfate. Insoluble in water.
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{| class="wikitable"
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|-
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! scope="row"| Composition
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| AgCN
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|-
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! scope="row"| CAS
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| 506-64-9
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|-
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! scope="row"| Melting Point
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| 320 C (dec)
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|-
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! scope="row"| Density
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| 3.95 g/ml
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|-
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! scope="row"| Molecular Weight
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| mol. wt. = 133.89
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|-
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! scope="row"| Refractive Index
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| 1.685, 1.94
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|}
  
 
==Resources and Citations==
 
==Resources and Citations==
  
* David C. Scott, ''Metallography and Microstructure of Ancient and Historic Metals'', The Getty Conservation Institute, Los Angeles, 1991
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* D. Strahan "Treatment of a Silver Dragon for the Removal of Silver Cyanide and Chalconatronite" ''JAIC'', 25: 73-81, 1986.
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* Richard S. Lewis, ''Hawley's Condensed Chemical Dictionary'', Van Nostrand Reinhold, New York, 10th ed., 1993
  
* ''The American Heritage Dictionary'' or ''Encarta'', via Microsoft Bookshelf 98, Microsoft Corp., 1998
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* ''The Merck Index'', Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983  Comment: entry 8655
  
* Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997
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* ''CRC Handbook of Chemistry and Physics'', Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980  Comment: ref. index = 1.685, 1.94
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Latest revision as of 10:35, 31 May 2022

Description

White or gray, granular powder that darkens on exposure to light. Silver cyanide is used primarily for silver plating. Some chemical tarnish removal methods use dilute cyanide solutions for dipping followed by a water rinse. Cyanide solutions will react with silver to produce silver cyanide residues which are highly toxic.

Risks

  • Highly toxic by ingestion, inhalation or skin absorption.
  • ThermoFisher: SDS

Physical and Chemical Properties

Soluble in solutions of ammonium hydroxide, nitric acid, potassium cyanide, potassium ferricyanide and sodium thiosulfate. Insoluble in water.

Composition AgCN
CAS 506-64-9
Melting Point 320 C (dec)
Density 3.95 g/ml
Molecular Weight mol. wt. = 133.89
Refractive Index 1.685, 1.94

Resources and Citations

  • D. Strahan "Treatment of a Silver Dragon for the Removal of Silver Cyanide and Chalconatronite" JAIC, 25: 73-81, 1986.
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8655
  • CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. index = 1.685, 1.94