Trisodium phosphate

From Wikipedia, the free encyclopedia - View original article

Trisodium phosphate[1]
Trisodium phosphateTrisodium phosphate 3D.jpg
Trisodium phosphate hydrate.jpg
Identifiers
CAS number7601-54-9 YesY
10101-89-0 (dodecahydrate)
PubChem24243
ChemSpider22665 YesY
UNIISX01TZO3QZ N
EC number231-509-8
KEGGD09000 YesY
ChEBICHEBI:37583 YesY
ChEMBLCHEMBL363100 YesY
RTECS numberTC9575000
ATC codeA06AD17,A06AG01 B05XA09
V10XX01 (32P)
Jmol-3D imagesImage 1
Properties
Molecular formulaNa3O4P
Molar mass163.94 g mol−1
Density2.536 g/cm3 (17.5 °C, anhydrous)
1.62 g/cm3 (20 °C, dodecahydrate)[2][3][4]
Melting point1,340 °C (2,440 °F; 1,610 K)
(anhydrous)[3]
73.4 °C (164.1 °F; 346.5 K)
(dodecahydrate)[4]
Boiling point100 °C (212 °F; 373 K) (dodecahydrate) decomposes[4]
Solubility in wateranhydrous:[3]
5.4 g/100 mL (0 °C)
12 g/100 mL (20 °C)[5]
14.5 g/100 mL (25 °C)
23.3 g/100 mL (40 °C)
94.6 g/100 mL (100 °C)
dodecahydrate:[4]
28.3 g/100 mL (20 °C)
Solubilityinsoluble in ethanol, CS2[4]
Basicity (pKb)2.23
Structure
Crystal structureTrigonal
Thermochemistry
Specific
heat capacity
C
665 J/mol·K (dodecahydrate)[4]
Std molar
entropy
So298
224.7 J/mol·K (anhydrous)[3]
660 J/mol·K (dodecahydrate)[4]
Std enthalpy of
formation
ΔfHo298
-1935.5 kJ/mol (anhydrous)[3]
-5480 kJ/mol (dodecahydrate)[4]
Gibbs free energy ΔG-1819 kJ/mol (anhydrous)[3]
Hazards
MSDSICSC 1178
GHS pictogramsThe corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[6]
GHS signal wordDanger
GHS hazard statementsH315, H318, H335[6]
GHS precautionary statementsP261, P280, P305+351+338[6]
EU IndexNot listed
EU classificationIrritant Xi
R-phrasesR36/37/38
S-phrasesS26
NFPA 704
Flash pointNon-flammable
Related compounds
Other cationsTripotassium phosphate
Triammonium phosphate
Trimagnesium phosphate
Related compoundsMonosodium phosphate
Disodium phosphate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references
 
Jump to: navigation, search
Not to be confused with Sodium triphosphate.
Trisodium phosphate[1]
Trisodium phosphateTrisodium phosphate 3D.jpg
Trisodium phosphate hydrate.jpg
Identifiers
CAS number7601-54-9 YesY
10101-89-0 (dodecahydrate)
PubChem24243
ChemSpider22665 YesY
UNIISX01TZO3QZ N
EC number231-509-8
KEGGD09000 YesY
ChEBICHEBI:37583 YesY
ChEMBLCHEMBL363100 YesY
RTECS numberTC9575000
ATC codeA06AD17,A06AG01 B05XA09
V10XX01 (32P)
Jmol-3D imagesImage 1
Properties
Molecular formulaNa3O4P
Molar mass163.94 g mol−1
Density2.536 g/cm3 (17.5 °C, anhydrous)
1.62 g/cm3 (20 °C, dodecahydrate)[2][3][4]
Melting point1,340 °C (2,440 °F; 1,610 K)
(anhydrous)[3]
73.4 °C (164.1 °F; 346.5 K)
(dodecahydrate)[4]
Boiling point100 °C (212 °F; 373 K) (dodecahydrate) decomposes[4]
Solubility in wateranhydrous:[3]
5.4 g/100 mL (0 °C)
12 g/100 mL (20 °C)[5]
14.5 g/100 mL (25 °C)
23.3 g/100 mL (40 °C)
94.6 g/100 mL (100 °C)
dodecahydrate:[4]
28.3 g/100 mL (20 °C)
Solubilityinsoluble in ethanol, CS2[4]
Basicity (pKb)2.23
Structure
Crystal structureTrigonal
Thermochemistry
Specific
heat capacity
C
665 J/mol·K (dodecahydrate)[4]
Std molar
entropy
So298
224.7 J/mol·K (anhydrous)[3]
660 J/mol·K (dodecahydrate)[4]
Std enthalpy of
formation
ΔfHo298
-1935.5 kJ/mol (anhydrous)[3]
-5480 kJ/mol (dodecahydrate)[4]
Gibbs free energy ΔG-1819 kJ/mol (anhydrous)[3]
Hazards
MSDSICSC 1178
GHS pictogramsThe corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)[6]
GHS signal wordDanger
GHS hazard statementsH315, H318, H335[6]
GHS precautionary statementsP261, P280, P305+351+338[6]
EU IndexNot listed
EU classificationIrritant Xi
R-phrasesR36/37/38
S-phrasesS26
NFPA 704
Flash pointNon-flammable
Related compounds
Other cationsTripotassium phosphate
Triammonium phosphate
Trimagnesium phosphate
Related compoundsMonosodium phosphate
Disodium phosphate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Trisodium phosphate (TSP) is the inorganic compound with the chemical formula Na3PO4. It is a white, granular or crystalline solid, highly soluble in water producing an alkaline solution. TSPs are used as cleaning agent, lubricant, food additive, stain remover and degreaser.[7]

The item of commerce is often partially hydrated and may range from anhydrous Na3PO4, to the dodecahydrate, Na3PO4·12 H2O. Most often found in white powder form, it can also be called trisodium orthophosphate or simply sodium phosphate.

Production[edit]

Trisodium phosphate is produced by neutralization of phosphoric acid using sodium hydroxides, often with sodium carbonate. Carbonate can only produce disodium phosphate:

Na2CO3 + H3PO4 → Na2HPO4 + CO2 + H2O
Na2HPO4 + NaOH → Na3PO4 + H2O

Uses[edit]

Cleaning[edit]

Trisodium phosphate was at one time extensively used in formulations for a variety of consumer grade soaps and detergents, and the most common use for trisodium phosphate has been in cleaning agents. The pH of a 1% solution is 12 (i.e., very basic), and the solution is sufficiently alkaline to saponify grease and oils. In combination with surfactants, TSP is an excellent agent for cleaning everything from laundry to concrete driveways. This versatility and low manufacturing price made TSP the basis for a plethora of cleaning products sold in the mid-20th century. TSP is still sold and used as a cleaning agent but since the late 1960s its use has diminished in the United States and many other parts of the world because like many phosphate-based cleaners it is known to cause extensive eutrophication of lakes and rivers once it enters a water system.[8] Substitutes are generally not as effective.[9]

TSP is commonly used after cleaning a surface with mineral spirits in order to remove hydrocarbon residues[citation needed] and may be used with household chlorine bleach in the same solution without hazardous reactions.[10] This mixture is particularly effective for removing mildew, but is less effective at removing mold.

Although it is still the active ingredient in some toilet bowl cleaning tablets, TSP is generally not recommended for cleaning bathrooms because it can stain metal fixtures and can damage grout.[11]

Chlorinated trisodium phosphate[edit]

With the formula Na3PO4.¼ NaOCl.11 H2O, the material called chlorinated trisodium phosphate is used as a disinfectant and bleach, like sodium hypochlorite. It is prepared using NaOCl in place of some of the base to neutralize phosphoric acid.[7]

Flux[edit]

In the U.S., trisodium phosphate is an approved flux for use in hard soldering joints in medical grade copper plumbing. The flux is applied as a concentrated water solution and dissolves copper oxides at the temperature used in copper brazing. Residues are water soluble and can be rinsed out before plumbing is put into service.

TSP is used as an ingredient in fluxes designed to deoxygenate nonferrous metals for casting. It can be used in ceramic production to lower the flow point of glazes.

Painting enhancement[edit]

TSP is still in common use for the cleaning, degreasing and deglossing of walls prior to painting. TSP breaks the gloss of oil based paints and opens the pores of latex based paint providing a surface better suited for the adhesion of the subsequent layer.[12][unreliable source?]

Food additive[edit]

Sodium phosphates including monosodium phosphate, disodium phosphate, and trisodium phosphate are approved as food additives in the EU. They are used as antioxidant agents and have the collective E number E339.[13] In the United States, sodium phosphates are categorized as generally recognized as safe when used in accordance with good manufacturing practice.[14] Trisodium phosphate is commonly found in many brands of children's cereal, toothpaste, processed cheese, meats, and canned soups. [15][unreliable source?]

Exercise performance enhancement[edit]

Trisodium phosphate has gained a following as a nutritional supplement that can improve certain parameters of exercise performance.[16] The basis of this belief is the fact that phosphate is required for the energy-producing Krebs cycle central to aerobic metabolism. Phosphates are available from a number of other sources that are much milder than TSP. While TSP is not toxic per se, it is severely irritating to gastric mucosa unless used as part of a buffered solution.

Regulation[edit]

In the western world, phosphate usage has declined owing to ecological problems with the damage to lakes and rivers through eutrophication.

TSP Substitutes[edit]

By the end of the 20th century, many products that formerly contained TSP were manufactured with TSP substitutes, which consist mainly of sodium carbonate along with various admixtures of nonionic surfactants and a limited percentage of sodium phosphates.

Products sold as TSP substitute, containing soda ash and zeolites, are promoted as a direct substitute. However, sodium carbonate is not as strongly basic as trisodium phosphate, making it less effective in demanding applications. Zeolites are added to laundry detergents as bulking agents that rapidly break down in water and are essentially nonpolluting. Cleaning products labeled as TSP may contain other ingredients, with perhaps less than 50% trisodium phosphate.[17]

See also[edit]

References[edit]

  1. ^ Merck Index, 12th Edition, 8808.
  2. ^ Eagleson, Mary, ed. (1994). [Google Books Concise Encyclopedia Chemistry]. Walter de Gruyter. p. 1000. ISBN 3110114518. Retrieved 2014-05-25. 
  3. ^ a b c d e f http://chemister.ru/Database/properties-en.php?dbid=1&id=780
  4. ^ a b c d e f g h http://chemister.ru/Database/properties-en.php?dbid=1&id=781
  5. ^ http://www.vinvicta.com.au/information/TrisodiumPhosphateMSDS.pdf
  6. ^ a b c Sigma-Aldrich Co., Sodium phosphate. Retrieved on 2014-05-25.
  7. ^ a b Klaus Schrödter, Gerhard Bettermann, Thomas Staffel, Friedrich Wahl, Thomas Klein, Thomas Hofmann "Phosphoric Acid and Phosphates" in Ullmann’s Encyclopedia of Industrial Chemistry 2008, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_465.pub3
  8. ^ Dishes Still Dirty? Blame Phosphate-Free Detergent, National Public Radio, December 15, 2010
  9. ^ Hotton, Peter (26 August 2010). "Handyman on Call". The Boston Globe. 
  10. ^ Home Improvement — General — House siding, allexperts.com
  11. ^ "TSP ... Cleaning for the Big Dogs". Home Repair and Do It Yourself Tips and Articles from the Natural Handyman. Natural Handyman. 
  12. ^ Alonzy, Jerry. "Painting Preparation Q&A". 
  13. ^ Current EU approved additives and their E Numbers, Food Standards Agency, 26 November 2010
  14. ^ 21CFR182.1778, Code of Federal Regulations
  15. ^ http://naturalsociety.com/paint-thinner-kids-cereals-fda-approved/
  16. ^ Folland JP et al. (2008). "Sodium phosphate loading improves laboratory cycling time-trial performance in trained cyclists.". Journal of Science and Medicine in Sport 11 (5): 464–468. doi:10.1016/j.jsams.2007.04.004. PMID 17569583. 
  17. ^ MSDS for Dap TSP cleaner

External links[edit]