Monosodium phosphate

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(Redirected from
Sodium dihydrogen phosphate
)
Monosodium phosphate
Ball-and-stick model of the dihydrogenphosphate anion
  Phosphorus, P
  Oxygen, O
  Hydrogen, H
  Sodium, Na
Names
IUPAC name
Sodium dihydrogen phosphate
Other names
  • Monobasic sodium phosphate
  • Sodium biphosphate
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.028.591 Edit this at Wikidata
E number E339(i) (antioxidants, ...)
UNII
  • InChI=1S/Na.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+1;/p-1 checkY
    Key: AJPJDKMHJJGVTQ-UHFFFAOYSA-M checkY
  • [Na+].[O-]P(=O)(O)O
Properties
NaH2PO4
Molar mass 119.976 g·mol−1
Appearance White powder or crystals
Density 2.36 g/cm3 (anhydrous)
59.90 g/(100 mL) (0°C)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
0
0
Flash point Non-flammable
Related compounds
Other cations
  • Monoammonium phosphate
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Monosodium phosphate (MSP), also known as monobasic sodium phosphate and sodium dihydrogen phosphate, is an

sodium phosphates, it is a common industrial chemical. The salt exists in an anhydrous form, as well as monohydrate and dihydrate (NaH2PO4·H2O and NaH2PO4·2H2O respectively).[1]

Production and reactions

The salt is obtained by partial neutralization of

pKa of monosodium phosphate is 6.8-7.2 (depending on the physicochemical characteristics during pKa determination).[2]

Heating this salt above 169 °C gives disodium pyrophosphate:

2 NaH2PO4 → Na2H2P2O7 + H2O

When heated at 550 °C,

trisodium trimetaphosphate is formed:[3]

3 NaH2PO4 → Na3P3O9 + 3 H2O

Uses

Phosphates are often used in foods and in water treatment. The

sodium phosphates, such as this salt.[1]
The sodium chloride equivalent value, or E-Value, is 0.49.[clarification needed] It is soluble in 4.5 parts water.[clarification needed]

Food additive

It is added in

emulsifier
.

Detection of magnesium

Monosodium phosphate is used to detect the presence of

aqueous or dilute HCl
solution of the salt indicates presence of magnesium ions.

Notes

  1. ^
    ISBN 978-3527306732
    .
  2. ^ Salaun, F.: "Influence of mineral environment on the buffering capacity of casein micelles" Archived 2012-03-13 at the Wayback Machine, "Milchwissenschaft", 62(1):3
  3. ISBN 9780470132340
    .
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