Potassium persulfate Chemical Properties

Melting point:

1067 °C

Boiling point:

1689 °C

Density 

2.47

vapor density 

9.3 (vs air)

vapor pressure 

0Pa at 25℃

storage temp. 

Store at +5°C to +30°C.

solubility 

H₂O: 0.5 M at 20 °C, clear, colorless

form 

Solid

Specific Gravity

2.477

color 

White

PH

3.2 (50g/l, H2O, 20℃)

Odor

Odorless

PH Range

2.5 - 4.5

Water Solubility 

5 g/100 mL (20 ºC)

Merck 

14,7656

Exposure limits

ACGIH: TWA 0.1 mg/m3

Stability:

Stable. Strong oxidizer. Incompatible with strong reducing agents, organic materials, combustible materials.

InChIKey

USHAGKDGDHPEEY-UHFFFAOYSA-L

LogP

-1 at 20℃

CAS DataBase Reference

7727-21-1(CAS DataBase Reference)

EPA Substance Registry System

Potassium persulfate (7727-21-1)

Safety Information

Hazard Codes 

O,Xn

Risk Statements 

8-22-36/37/38-42/43

Safety Statements 

22-24-26-37

RIDADR 

UN 1492 5.1/PG 3

WGK Germany 

1

RTECS 

TT5900000

TSCA 

Yes

HS Code 

2833 40 00

HazardClass 

5.1

PackingGroup 

III

Hazardous Substances Data

7727-21-1(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: 802 mg/kg

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Potassium persulfate Usage And Synthesis

Outline

Potassium persulfate (Formula is K2S2O8) is also known as potassium peroxydisulfate, molecular weight is 270.32, decomposition temperature is 50-60℃, it is white, odorless crystal, it is soluble in water, insoluble in alcohol, it has strong oxidizing, it is commonly used as bleaching agents, oxidizing agents, it can be used as the polymerization initiator, it almost does not absorb moisture, it has good stability at room temperature, it is easy to be stored, and it has the advantages of convenience and safety, etc. . Applications involves polymerization initiator, circuit board cleaning and etching, copper and aluminum surface activation, modified starch, pulp and textile bleaching and desizing low temperature, circulating water purification treatment systems, oxidative degradation of harmful gases, low formaldehyde adhesive stick together accelerated oxidation of ethanol and aromatic hydrocarbons, disinfectants, hair dye decolorization.
The above information is edited by the chemicalbook of Wang Xiaodong.

Half-life

80℃-1.5 hours; 70℃-7.7 hours; 60℃-33 hours; 45℃-292 hours; 35℃-1600 hours.

Recrystallization

Potassium persulfate dissolves in 30℃ water, cools, then the recrystallized product can be obtained, it is filtered and dried under reduced pressure in the presence of calcium chloride.

Solubility in water(g/100ml)

Grams which dissolves in per 100 ml of water: 4.7g/20 ℃.

The main application areas

Potassium persulfate is mainly used as initiator and strong oxidizing agents.
Initiator:
Potassium persulfate is the initiator of latex or solution polymerization of acrylic monomers, vinyl acetate, vinyl chloride and other product, and it is also the initiator of styrene, acrylonitrile, butadiene and the like emulsion for copolymerisation.
Strong oxidizing agent:
1. It is used as desizing agent and bleach activator.
2. It is used for oxidative degradation of harmful substances in pool and closed circular loop in water.
3. It can be applied in the production of starch modifier and applied in the production of adhesive and coating agent.
4. It can be applied in the branched-chain oxidation, alcohol and aromatic hydroxy oxidation.
5. It is one of the basic constituent of hair dyes, it plays the role of decolorization.

Toxicity

The amount is not specified (FAO/WHO, 2001).
Potassium persulfate powder has stimulating effect on nasal mucosa, packaging should be ventilated to prevent dust. Labour protection appliance should be dressed at work.

Storage precautions

Potassium persulfate is non-flammable, it is combustion-supporting which due to it can release of oxygen, storage environment must be dry and clean, well-ventilated. Pay attention to moisture and rain, it should not be transported in rain. Keep away from fire, heat and direct sunlight. It should be kept sealed packaging, labels should be intact and clear. It should be stored separately with flammable or combustible materials, organic compounds, as well as rust, small amount of metal, and other reducing substance, it should avoid mix to prevent causing decomposition of potassium persulfate and explosion.

Chemical properties

It is colorless or white triclinic crystalline powder. It is soluble in water, the solubility is 1.75g/100ml water at 0℃, the solubility is 5.3g/100ml water at 20℃. It is insoluble in alcohol. Queous solution is acidic.

Uses

It can be used as gluten agent of wheat flour.
It is mainly used as a disinfectant and fabric bleach. It can be used as industrial oxidant in dyes and inorganic salts. It can be used as emulsion polymerization initiators in synthetic rubber industry. It can be used as polymerization accelerator in synthetic resin. In addition, it can also be used in the steel, photographic industry and medicine.
It can be used as analytical reagents, oxidants and plastic initiator, it can also be used in the film photofinishing.
The above information is edited by the chemicalbook of Wang Xiaodong.

Production method

Potassium sulfate method
Ammonium sulfate and sulfuric acid formulates to form liquid electrolyte, it is decontaminated by electrolysis, HSO4-can discharge and generate peroxydisulfate acidat in the anode, and then reacts with ammonium sulfate to generate ammonium persulfate, Then replacement reaction can happen when potassium is added . The finished product of potassium persulfate can be obtained after cooling, separation, crystallization, drying.
Anode reaction: 2HSO4-2e → H2S2O8
Cathodic reaction: 2H ++ 2e → H2 ↑
(NH4) 2SO4 + H2S2O8 → (NH4) 2S2O8 + H2SO4
(NH4) 2S2O8 + K2SO4 + H2SO4 → K2S2O8 + 2NH4HSO4
It can be derived by replacement reaction with ammonium persulfate potassium sulfate, then it goes through cooling, separation, crystallization, drying.

Category

oxidant

Toxicity grading

Mid toxicity.

Acute toxicity

Oral-rat LD50: 802 mg/kg.

Explosive hazardous characteristics

It can explode when mixes with reductant, sulfur, phosphorus; It can explode when be heated, impacted, and meets fire.

Flammability hazard characteristic

Thermal decomposition can get oxygen; toxic fumes of nitrogen oxides can generate after combustion.

Storage characteristics

Treasury should have ventilation and be low-temperature drying; loading and unloading should be light; it should be stored separately with organic matter, reducing agents, sulfur, phosphorus combustibles.

Extinguishing agent

Mist of water, sand, foam.

Professional standards

TWA 2 mg/m.

Description

Potassium persulfate, is composed of white crystals that are soluble in water, and it decomposes below 212°F (100°C). Potassium persulfate is a dangerous fire risk in contact with organic materials. It is a strong oxidizing agent and an irritant, with a four-digit UN identification number of 1492. The primary uses are in bleaching, as an oxidizing agent, as an antiseptic, as a polymerization promoter, and in the manufacture of pharmaceuticals.

Chemical Properties

colourless odourless crystals or white powder

Chemical Properties

Potassium persulfate is a colorless or white, odorless crystalline material.

Physical properties

Colorless or white crystals; triclinic structure; density 2.477 g/cm³; stable in solid crystalline form; decomposes on heating, evolving oxygen; completely decomposes at about 100°C; sparingly soluble in cold water 1.75 g/100mL at 0°C; moderately soluble at ordinary temperature, 5.29 g/100 mL at 20°C;aqueous solution acidic and unstable, decomposing slowly at room temperature and more rapidly when the solution is warmed; insoluble in alcohol.

Uses

Potassium persulfate?is a powerful oxidant, commonly used to initiate polymerizations. Potassium Persulphate used for bleaching and textile desizing, as an oxidizing agent and antiseptic, in purification of ammonium sulfate, and in the manufacture of soap and pharmaceuticals. It is also used as al laboratory oxidant and photography chemical. It is a food additive.

Uses

Potassium persulfate is used to initiate the polymerization of styrene to form monodispersed, surfactant-free polystyrene spheres. Potassium persulfate is used as an oxidant to generate 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation to measure the antioxidant activities of natural compounds.

Uses

Bleaching fabrics, soaps; in photography under the name Anthion to remove last traces of thiosulfate from plates and paper; in analytical chemistry.

Preparation

Potassium persulfate can be prepared by electrolysis of a mixture of potassium sulfate and potassium hydrogen sulfate at a high current density:
2KHSO4→K₂S₂O₈+ H₂
Also, the compound can be prepared by adding potassium hydrogen sulfate,KHSOto an electrolyzed solution of ammonium hydrogen sulfate, NH₄HSO₄.

General Description

A white crystalline solid. Specific gravity 2.477. Decomposes below 100°C.

Air & Water Reactions

Water soluble. Slowly decomposed by water. The salt rapidly liberates oxygen when heated, and especially so when wet.

Reactivity Profile

Potassium persulfate is an oxidizing agent. Noncombustible but accelerates the burning of combustible material. Potassium persulfate plus a little potassium hydroxide and water released sufficient heat and oxygen to ignite a polythene (polyethylene) liner in a container. [MCA Case History 1155. 1955].

Hazard

Strong irritant and oxidizing agent. Fire risk in contact with organic materials.

Health Hazard

Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or death. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.

Fire Hazard

These substances will accelerate burning when involved in a fire. Some may decompose explosively when heated or involved in a fire. May explode from heat or contamination. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard.

Flammability and Explosibility

Non flammable

Agricultural Uses

Potassium sulphate, also called sulphate of potash, is a white crystalline material, moderately hygroscopic, available in fine, granular and semi-granular forms. It contains 48 to 54% potassium (as K₂O) and supplies 17 to 20 % of sulphate. Chloride-sensitive crops like tobacco, grapes and potato require chloride-free potassium fertilizers. Therefore, these crops are fertilized with potassium sulphate, although this is more expensive than potassium chloride. These three crops, being major crops, account for about 7% of the total potash consumption. For best results, potassium sulphate should contain at least 50 % potash by weight.
Potassium sulphate occurs in nature as 'langbeinite' , a double sulphate of potassium and magnesium (K₂SO_{4?2MgSO4) and made from burkeite (Na2CO3?2Na2SO4), kainite (KCl?MgS04?3H2O) or potassium chloride (KCl) as follows:
When applied to soil, potassium ion from the watersoluble potassium sulphate is retained in the soil colloids and not easily leached out. This makes potassium sulphate an excellent fertilizer, useful for all soils and crops while sowing or before sowing. It is also a safe ingredient of powdered, mixed fertilizers.}

Safety Profile

Moderately toxic by ingestion. An irritant and allergen. A powerful oxidtzer. Flammable when exposed to heat or by chemical reaction. Can react with reducing materials. It liberates oxygen above 100' when dry or @ about 50' when in solution. When heated to decomposition it emits highly toxic fumes of SOx,, S2O8, and K2O.

Potential Exposure

Potassium persulfate is used as a bleaching and oxidizing agent; it is used in redox polymeri- zation catalysts; in the defiberizing of wet strength paper and in the desizing of textiles. Soluble in water.

Shipping

UN1492 Potassium persulfate, Hazard Class: 5.1; Labels: 5.1-Oxidizer.

Purification Methods

Crystallise the persulfate twice from distilled water (10mL/g) and dry it at 50o in a vacuum desiccator. Its solubility in H2O is 1.6% at 0o, 4.5% at 20o, and 7.2% at 30o. An aqueous solution decomposes on long standing with evolution of O2 and formation of KHSO4. It is a powerful oxidising agent. Store it at ~10o. [Fehér in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 390 1963.]

Incompatibilities

A strong oxidizer. Incompatible with combustible, organic or other readily oxidizable materials; sulfur, metallic dusts, such as aluminum dust; chlorates and perchlorates. Attacks chemically active metals. Keep away from moisture.

Waste Disposal

Use large volumes of reducing agents (bisulfites, e.g.). Neutralize with soda ash and drain into sewer with abundant water.

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