Difference between pages "Black coral" and "Sodium dithionite"

Latest revision as of 16:35, 1 June 2022

Description

Pale yellow powder that is used as a Reducing agent in dyeing Indigo and vat dyes. Sodium dithionite is also used to strip dyes from dyed textiles and reduce iron oxide stains to Ferrous oxide. Sodium dithionite was also used as a bleach for Leather and mechanical paper pulps but its use has declined in recent years due to poor color reversion properties (AIC Book and Paper Catalog).

Note: this is not the same compound as Sodium thiosulfate (Na2S2O3; also called sodium hyposulfite) that is used for fixation in photography.

Chemical structure

Synonyms and Related Terms

sodium thiosulfite; sodium hydrosulfite; sodium sulfoxylate

Physical and Chemical Properties

Soluble in water (pH = 6.0-7.5 for 1-6% solution). Insoluble in ethanol.

Composition	Na2S2O4
CAS	7775-14-6
Melting Point	52-55 C
Density	2.19 g/ml
Molecular Weight	mol. wt. = 174.1

Risks

Fire risk in contact with moisture and air. Use dry sand to extinguish fires. Flash point=90 C
Contact causes irritation
Integra Chemc: SDS

Resources and Citations

G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 786

Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989

The Dictionary of Paper, American Paper Institute, New York, Fourth Edition, 1980

Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 8771

Wikipedia: http://en.wikipedia.org/wiki/Sodium_dithionite (Accessed Jan. 6 2006)

@@ Line 1: / Line 1: @@
-[[File:Black coral 2006611.jpg|thumb|Black coral<br>MFA# 2006.611]]
-[[File:image1_blackcoral.jpg|thumb|Black Coral on reef underwater]]
 == Description ==
-Any of several types of rare black-color [[coral]].  Black coral occurs as featherlike or treelike formations.  They grow in the Mediterranean Sea, the Caribbean Sea, the Gulf of Mexico near Panama, off the coast of southeastern Asia and Japan and in the Indian Ocean.  Carved pieces of black coral appeared similar to [[horn]] and can be polished to a high gloss (Untracht 1985).
+Pale yellow powder that is used as a [[reducing%20agent|reducing agent]] in dyeing [[indigo]] and [[vat%20dye|vat dyes]]. Sodium dithionite is also used to strip dyes from dyed textiles and reduce [[iron%20stain|iron oxide stains]] to [[ferrous%20oxide|ferrous oxide]]. Sodium dithionite was also used as a [[bleaching%20agent|bleach]] for [[leather]] and [[mechanical%20wood%20pulp|mechanical paper pulps]] but its use has declined in recent years due to poor color reversion properties (AIC Book and Paper Catalog).
+Note: this is not the same compound as [[sodium%20thiosulfate|sodium thiosulfate]] (Na2S2O3; also called sodium hyposulfite) that is used for fixation in photography.
+[[[SliderGallery rightalign|sodium dithionite.jpg~Chemical structure]]]
 == Synonyms and Related Terms ==
-akabar; giojetto
+sodium thiosulfite; sodium hydrosulfite; sodium sulfoxylate
+== Physical and Chemical Properties ==
+Soluble in water  (pH = 6.0-7.5 for 1-6% solution). Insoluble in ethanol.
+{| class="wikitable"
+|-
+! scope="row"| Composition
+| Na2S2O4
+|-
+! scope="row"| CAS
+| 7775-14-6
+|-
+! scope="row"| Melting Point
+| 52-55 C
+|-
+! scope="row"| Density
+| 2.19 g/ml
+|-
+! scope="row"| Molecular Weight
+| mol. wt. = 174.1
+|}
+== Risks ==
+* Fire risk in contact with moisture and air.  Use dry sand to extinguish fires.  Flash point=90 C
+* Contact causes irritation
+* Integra Chemc: [https://www.integrachem.com/msds/S365_26390_102.pdf SDS]
 ==Resources and Citations==
-* ''Encyclopedia Britannica'', http://www.britannica.com  Comment: "Coral." Accessed 22 Jan. 2004  .
+* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 786
+* Richard S. Lewis, ''Hawley's Condensed Chemical Dictionary'', Van Nostrand Reinhold, New York, 10th ed., 1993
+* Matt Roberts, Don Etherington, ''Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology'', U.S. Government Printing Office, Washington DC, 1982
+* Book and Paper Group, ''Paper Conservation Catalog'', AIC, 1984, 1989
+* ''The Dictionary of Paper'', American Paper Institute, New York, Fourth Edition, 1980
+* ''Van Nostrand's Scientific Encyclopedia'', Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
-* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p.235
+* ''The Merck Index'', Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983  Comment: entry 8771
-* Oppi Untracht, ''Jewelry Concepts and Technology'', Doubleday & Co., Inc., New York City, 1985
+* Wikipedia: http://en.wikipedia.org/wiki/Sodium_dithionite (Accessed Jan. 6 2006)
 [[Category:Materials database]]