Phosphotungstic acid hydrate

Synonym(s):Phosphotungstic acid;Tungstophosphoric acid;Tungstophosphoric acid hydrate

CAS NO.：12501-23-4
Empirical Formula: H3O41PW12(-2)
Molecular Weight: 2896.04
MDL number: MFCD00149915
EINECS: 603-020-3
SAFETY DATA SHEET (SDS)
Update Date: 2026-01-13 11:25:01

What is Phosphotungstic acid hydrate?

Chemical properties

Crystalline

The Uses of Phosphotungstic acid hydrate

Phosphotungstic acid hydrate has been a useful histology stain for cell specimens.

The Uses of Phosphotungstic acid hydrate

12-Tungstophosphate hydrate is used in histology as a component for staining of cell specimens. It binds to fibrin, collagen and fibers of connective tissues. It is also used to replace the anions of dyes from these materials. In solution, it acts as a homogeneous catalyst and involved in the hydrolysis of propene to give 2-propanol. It is supported with alumina and silica and act as a heterogeneous catalyst involved in the dehydration of 2-propanol to propene and methanol to hydrocarbons. In analytical chemistry, it is used to precipitate proteins and termed as "universal" precipitant for polar proteins.

The Uses of Phosphotungstic acid hydrate

Phosphotungstic acid hydrate may be used as a staining agent for the transmission electron microscope (TEM) imaging of cetyltrimethylammonium bromide (CTAB) coated gold nanorods.
It may be used in the preparation of:

Phosphotungstic acid doped ormosil hybrid networks.
Niobia supported phosphotungstic acid (PTA) catalysts.
Titanium dioxide (TiO₂) nanoparticles /phosphotungstic acid (HPW) films.

What are the applications of Application

Phosphotungstic acid is a useful histology stain for cell specimens

General Description

Phosphotungstic acid hydrate is a heteropolyacid.

Flammability and Explosibility

Not classified

Purification Methods

A few drops of conc HNO3 are added to 100g of phosphotungstic acid dissolved in 75mL of water, in a separating funnel, and the solution is extracted with diethyl ether. The lowest of the three layers, which contains a phosphotungstic acid-ether complex, is separated, washed several times with 2M HCl, then with water and again extracted with ether. Evaporation of the ether under vacuum with mild heating on a water bath gives crystals which are dried under vacuum and ground [Matijevic & Kerker, J Am Chem Soc 81 1307 1959].

Properties of Phosphotungstic acid hydrate

Melting point:	~95 °C(lit.)
Boiling point:	107.9℃[at 101 325 Pa]
Density	3.88[at 20℃]
vapor pressure	19.2hPa at 20℃
storage temp.	room temp
form	Solid
color	White
PH	1.3 (20g/l, H2O, 20℃)
Water Solubility	soluble
Sensitive	Hygroscopic
Exposure limits	ACGIH: TWA 3 mg/m3 NIOSH: TWA 5 mg/m3; STEL 10 mg/m3
Stability:	hygroscopic
CAS DataBase Reference	12501-23-4(CAS DataBase Reference)

Safety information for Phosphotungstic acid hydrate

Signal word	Danger
Pictogram(s)	Corrosion Corrosives GHS05 Exclamation Mark Irritant GHS07 Environment GHS09
GHS Hazard Statements	H302:Acute toxicity,oral H314:Skin corrosion/irritation H411:Hazardous to the aquatic environment, long-term hazard
Precautionary Statement Codes	P260:Do not breathe dust/fume/gas/mist/vapours/spray. P273:Avoid release to the environment. P280:Wear protective gloves/protective clothing/eye protection/face protection. P301+P312:IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell. P303+P361+P353:IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.