Name | Chromium Potassium Sulfate dodecahydrate |
Synonyms | Potassiumchromiumsulfate,doe potassiumchromiumalumdodecahydrate chromicpotassiumsulfatedodecahydrate Chromium (III) Potassium Dodecahydrate Chromium Potassium Sulfate dodecahydrate Chromium(Ⅲ) potassium sulfate dodecahydrate chromicpotassiumsulfatedodecahydrate(chromealum) dichromic dipotassium tetrasulfate tetracosahydrate CHROMIUM POTASSIUM SULFATE, REAGENT (ACS)CHROMIUM POTASSIUM SULFATE, REAGENT (ACS)CHROMIUM POTASSIUM SULFATE, REAGENT (ACS)CHROMIUM POTASSIUM SULFATE, REAGENT (ACS) |
CAS | 7788-99-0 |
EINECS | 616-539-5 |
InChI | InChI=1/2Cr.2K.4H2O4S.24H2O/c;;;;4*1-5(2,3)4;;;;;;;;;;;;;;;;;;;;;;;;/h;;;;4*(H2,1,2,3,4);24*1H2/q2*+3;2*+1;;;;;;;;;;;;;;;;;;;;;;;;;;;;/p-8 |
Molecular Formula | CrH24KO20S2 |
Molar Mass | 499.4 |
Density | 1.83 |
Melting Point | 89°C(lit.) |
Water Solubility | 24 g/100 mL (15 ºC) |
Solubility | Soluble in water and dilute acid, insoluble in alcohol, almost insoluble in alcohol. |
Appearance | Purple crystal |
Color | Violet |
Odor | Odorless |
Exposure Limit | NIOSH: IDLH 25 mg/m3; TWA 0.5 mg/m3 |
Merck | 14,2229 |
PH | 3 (50g/l, H2O, 20℃) |
Storage Condition | Store at +15°C to +25°C. |
Stability | Stable. Incompatible with magnesium, aluminium. |
Sensitive | Easily absorbing moisture |
MDL | MFCD00149917 |
Physical and Chemical Properties | Characteristics of purple or purple red equiaxed crystal octahedral crystal, easy to make large particle crystal. melting point 89 ℃ relative density 1.826(25 ℃) solubility soluble in water, dilute acid, insoluble in alcohol. |
Use | Used as tanning agent, mordant and photographic fixer |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/38 - Irritating to eyes and skin. |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. S37/39 - Wear suitable gloves and eye/face protection S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | 2 |
RTECS | GB6850000 |
TSCA | Yes |
HS Code | 28332990 |
Raw Materials | Sulfuric acid Potassium dichromate |
Black-purple shiny crystals or light purple granules or powders. Melting point 89 degrees C; d25 1.83. Dissolve in 4 parts of cold water, 2 parts of boiling water. Practically insoluble in ethanol. Easy weathering, in the transmission of light is red, heated to 100 deg C lost some crystal water and become green, 110 deg C to two water, 400 deg C into a pale yellow-green water, and lose water solubility. Its aqueous solution is purple when cold and green when hot.
potassium dichromate was dissolved in hot water and filtered. Concentrated sulfuric acid was added to the filtrate, followed by gradual addition of ethanol. When the liquid turned dark green, the addition of ethanol was continued until no further change occurred, I .e., the end point of the reaction was reached. The solution was evaporated, water was added to a relative density of 1.5 and then left to stand to crystallize. The crystals were removed by Suction filtration and sufficiently dried.
used as an analytical reagent. In the case of producing dyes such as active red brown K-B3R, neutral purple BL, neutral orange RL, and neutral pink BL, it is used as a chromium complexing agent and as a mordant for printing and dyeing in a photographic fixing solution as a hard film agent for photographic film. Also used in glass, ceramics and other fields.
toxic; If there is sodium dichromate solution or powder on the skin, it should be immediately rinsed with a large amount of water, the maximum allowable concentration in the air is 0. Olmg/m3. Above this concentration, inhalation can cause ulceration of the nasal mucosa. It cannot be stored and mixed with edible articles, flammable articles and acids.
Introduction | potassium chromium sulfate is a dark purple shiny crystal or light purple particles or powder. Soluble in water, the solution is cool when purple. Green when hot, insoluble in alcohol. Toxic. Easy to make large particles of crystals. Relative density 1.826(25 degrees C). Melting point 89 °c. Ten crystals of water were lost when heated to 100 °c, and twelve crystals of water became anhydrous when heated to 400 °c. Soluble in water, dilute acid, insoluble in alcohol. Dissolved in water as a purple red aqueous solution, heated to 70 ° C when the green solution, after cooling the gradient purple. Easy to absorb moisture, can be weathered in dry air. |
Application | (1) chrome tanning liquor in tanning industry;(2) Mordant for textile industry;(3) photographic fixer;(4) ceramic ware. For the analysis of reagents, but also as a water-repellent, for oil drilling and so on. |
preparation | after 98% potassium dichromate and 98% sulfuric acid are dissolved in the mother liquor of chromium alum according to the theoretical amount, the reduction was carried out by slow addition of wood chips with stirring. The reaction temperature is controlled at not more than 80 ° C. After the reaction is finished, the reaction is left to slowly crystallize. After the mother liquor is separated by centrifugation, the crystals are washed with a small amount of cold water, and then dried at low temperature, A finished product of potassium chromium sulfate was obtained. The reaction formula is as follows: 2K2Cr2O7+8H2SO4 + 40H2O + 3C → 4KCr(SO4)2 · 21H2O +3CO2 |
Use | used as tanning agent, printing and dyeing mordant and photographic fixer used as tanning agent, mordant and photographic fixative, etc. For microscopic analysis with fixing agent, leather, preparation of other chromium salts. used as analytical reagent, also used in photographic plate |
category | toxic substances |
toxicity grade | poisoning |
Acute toxicity | intravenous-mouse LD50: 112 mg/kg |
flammability hazard characteristics | , potassium oxide and sulfur oxide fumes|
storage and transportation characteristics | warehouse low temperature, ventilation, dry |
extinguishing agent | water, carbon dioxide, dry powder, sand |
Occupational Standard | TWA 0.5 mg (chromium)/m3 |