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POTASSIUM HYDROXIDE
| Potassium hydroxide |
 |
| General |
| Other names |
Potash lye |
| Molecular formula |
KOH |
| Molar mass |
56.11 g/mol |
| Appearance |
white solid,
deliquescent |
| CAS number |
[1310-58-3] |
| Properties |
| Density and phase |
2.044 g/cm3, solid |
| Solubility in water |
1100 g/L (25 °C) |
| Melting point |
406 °C |
| Boiling point |
1320 °C |
| Vapour Pressure |
1.3hPa (719 ° C) |
| Basicity (pKb) |
0 |
| Structure |
Coordination
geometry |
? |
| Crystal structure |
? |
| Hazards |
| MSDS |
External MSDS |
| EU classification |
Corrosive (C) |
| NFPA 704 |
|
| R-phrases |
R22, R35 |
| S-phrases |
S1/2, S26, S36/37/39, S45 |
| Flash point |
non flammable |
| RTECS number |
TT2100000 |
| Supplementary data page |
Structure and
properties |
n, εr, etc. |
Thermodynamic
data |
Phase behaviour
Solid, liquid, gas |
| Spectral data |
UV, IR, NMR, MS |
| Related compounds |
| Other anions |
Potassium oxide
Potassium peroxide
Potassium superoxide |
| Other cations |
Lithium hydroxide
Sodium hydroxide
Rubidium hydroxide
Caesium hydroxide |
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references |
The chemical compound potassium hydroxide, (KOH) sometimes known as caustic potash, potassa, potash lye, and potassium hydrate, is a metallic base. It is very alkaline.
Uses
In agriculture is used to correct the pH of acidic soils. It can also be used as a fungicide or even an herbicide.
It is a major industrial chemical used as a base in a wide variety of chemical processes. Some uses of KOH include acrylate ester copolymer coating, defoaming agents used in the manufacture of paper, formulation aid for food, pH control agent, polyethylene resins, textile processing and as a catalyst in reactions like the production of biodiesel.
Other uses include in veterinary medicine in disbudding calves horns and to dissolve scales and hair; in human medicine, to diagnose fungal infections and as a wart and cuticle solvent; manufacture of cleansers. This type of compound is also used in washing powders, some denture cleaners, non-phosphate detergents, and drain or pipe cleaners.
A very significant use of KOH in terms of significance to the average person is that alkaline batteries use an aqueous solution of KOH as an electrolyte. Thus, potassium hydroxide helps to power flashlights, smoke detectors, and other battery powered household items.
It is also an anisotropic etchant of silicon, exposing octahedral planes. This technique can create pyramyds and regularly-shaped etch pits for uses such as MEMS.
Food preparation
Food uses of lye include washing or chemical peeling of fruits and vegetables, chocolate and cocoa processing, caramel color production, poultry scalding, soft drink processing, and thickening ice cream. Olives are often soaked in lye to soften them, while pretzels and German lye rolls are glazed with a lye solution before baking to make them crisp.
Lye is used to make the Scandinavian delicacy known as lutefisk (from lutfisk, "lye fish"). Cod is soaked in lye to a jelly-like consistency, then served with bacon fat, potatoes, brunost sauce and mushy peas. Hominy is dried maize (corn) kernels reconstituted by soaking in lye
See also
External links
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