Ammonium hexafluorosilicate Property

Melting point:

°Cd ec.)

Density 

2.01 g/mL at 25 °C(lit.)

vapor pressure 

9.99Pa at 20℃

solubility 

water solubility 18 g/100 g water.

form 

Crystalline Powder and Chunks

Specific Gravity

2.011

color 

White

Water Solubility 

Slightly soluble in water. Insoluble in alcohol and acetone.

Hydrolytic Sensitivity

0: forms stable aqueous solutions

Merck 

14,527

Exposure limits

ACGIH: TWA 2.5 mg/m3
NIOSH: IDLH 250 mg/m3; TWA 2.5 mg/m3

InChI

InChI=1S/F6Si.2H3N/c1-7(2,3,4,5)6;;/h;2*1H3/q-2;;/p+2

InChIKey

ITHIMUMYFVCXSL-UHFFFAOYSA-P

SMILES

[Si-2](F)(F)(F)(F)(F)F.[NH4+].[NH4+]

LogP

-6.01 at 20℃

CAS DataBase Reference

16919-19-0(CAS DataBase Reference)

EPA Substance Registry System

Ammonium silicofluoride (16919-19-0)

Safety

Hazard Codes 

T

Risk Statements 

23/24/25

Safety Statements 

26-45

RIDADR 

UN 2854 6.1/PG 3

WGK Germany 

2

RTECS 

VV7800000

Hazard Note 

Toxic

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

III

HS Code 

2826908090

Hazardous Substances Data

16919-19-0(Hazardous Substances Data)

Toxicity

LD orally in guinea pigs: 150 mg/kg (Simonin, Pierron)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

Ammonium hexafluorosilicate Chemical Properties,Usage,Production

Chemical Properties

white slightly adhering crystalline powder

Chemical Properties

Ammonium hexafluorosilicate is a white crystalline powder. Odorless.

Physical properties

d 2.01 g cm?3; decomposes prior to melting; odorless.

Uses

Ammonium hexafluorosilicate is used as a disinfectant and analytical reagent. It finds application in etching glass, metal casting, and electroplating. It is also employed as a wood preservative agent and mothproofing agent in textiles. It plays a useful application in soldering flux. It is also used to arrest caries treatment without discoloration on demineralized primary tooth enamel.

Uses

In pesticides; in soldering flux; etching glass.

Preparation

By reacting crude quartz with ammonium fluoride or ammonium hydrodifluoride or a mixture thereof in an aqueous medium when heated from 50 ° to 110 ° C. to form ammonium hexafluorosilicate, separating it from unreacted quartz and insoluble impurities by known methods (filtration or centrifugation) and subsequent concentration and cooling of the mother liquor for crystallization of Ammonium hexafluorosilicate.

General Description

A white crystalline solid. Noncombustible. Corrodes aluminum. Used as a disinfectant, in etching glass, metal casting, and electroplating.

Air & Water Reactions

Water soluble.

Reactivity Profile

Salts, basic, such as Ammonium hexafluorosilicate, are generally soluble in water. The resulting solutions contain moderate concentrations of hydroxide ions and have pH's greater than 7.0. They react as bases to neutralize acids. These neutralizations generate heat, but less or far less than is generated by neutralization of the bases in reactivity group 10 (Bases) and the neutralization of amines. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible.

Hazard

Very toxic; fatal.

Health Hazard

Inhalation of dust can cause pulmonary irritation and can be fatal in some cases. Ingestion may be fatal. Contact with dust causes irritation of eyes and irritation or ulceration of skin.

Fire Hazard

Special Hazards of Combustion Products: Toxic and irritating hydrogen fluoride, silicon tetrafluoride, and oxides of nitrogen may form in fires.

Flammability and Explosibility

Not classified

Potential Exposure

This material is used as a pesticide and miticide, wood preservative, soldering flux; light metal casting; and in the etching of glass.

Shipping

UN2856 Fluorosilicates, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Purification Methods

Crystallise the salt from water (2mL/g). After 3 recrystallisations, the Technical grade salt has Li, Na, K and Fe at 0.3, 0.2, 0.1 and 1.0 ppm respectively.

Incompatibilities

Aqueous solution is highly corrosive. Contact with acids reacts to form hydrogen fluoride, which is a highly corrosive and forms a toxic gas. Corrosive to aluminum. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Ammonium fluorosilicate reacts with water to form hydrofluoric acid, a source of fluoride ions. Unlike other halide ions, the fluoride ion is highly reactive, acting as a weak base and participating in some unique reactions. In particular, fluorides react strongly with compounds containing calcium, magnesium, or silicon ions, which means that solutions containing soluble fluorides are corrosive to both living tissue and glass. Hydrofluoric acid can cause severe chemical burns and is one of the few materials that can etch glass. It is also a toxic gas in its anhydrous form.

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. Incineration.