Potassium Hydroxide (Koh)
Potassium Hydroxide (KOH)
Introduction
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash. Along with sodium hydroxide (NaOH), this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive nature. In 2005, an estimated 700,000 to 800,000 tonnes were produced. Approximately 100 times more NaOH than KOH is produced annually. KOH is noteworthy as the precursor to most soft and liquid soaps as well as numerous potassium-containing chemicals. Other names are Caustic Potash, Potash Lye, Potassia or Potassium Hydrate.
Properties
Potassium hydroxide can be found in pure form by reacting sodium hydroxide with impure potassium. Potassium hydroxide is usually sold as translucent pellets, which will become tacky in air because KOH is hygroscopic. Consequently, KOH typically contains varying amounts of water (as well as carbonates; see below). Its dissolution in water is strongly exothermic, meaning the process gives off significant heat. Concentrated aqueous solutions are sometimes called potassium lyes. Even at high temperatures, solid KOH does not dehydrate readily. Other info is:-
Physical Properties
1. Molecular formula KOH
2. Molar mass 56.1056 g/mol
3. Appearance white solid, deliquescent
4. Odor Odorless
5. Density 2.044 g/cm3
6. Melting point 406 °C, 679 K, 763 °F
7. Boiling point 1327 °C, 1600 K, 2421 °F
8. Solubility in water 97 g/100 mL (0 °C)
121 g/100 mL (25 °C)
178 g/100 mL (100 °C)
9. Solubility soluble in alcohol, glycerol insoluble in ether, liquid ammonia
10. Acidity (pKa) 13.5 (0.1 M)
11. Refractive index (nD) 1.409
12. Crystal structure rhombohedral
Structure
At higher temperatures, solid KOH crystallizes in the NaCl crystal structure. The OH group is either rapidly or randomly disordered so that the OH− group is effectively a spherical anion of radius 1.53 Å (between Cl− and F−
Introduction
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash. Along with sodium hydroxide (NaOH), this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive nature. In 2005, an estimated 700,000 to 800,000 tonnes were produced. Approximately 100 times more NaOH than KOH is produced annually. KOH is noteworthy as the precursor to most soft and liquid soaps as well as numerous potassium-containing chemicals. Other names are Caustic Potash, Potash Lye, Potassia or Potassium Hydrate.
Properties
Potassium hydroxide can be found in pure form by reacting sodium hydroxide with impure potassium. Potassium hydroxide is usually sold as translucent pellets, which will become tacky in air because KOH is hygroscopic. Consequently, KOH typically contains varying amounts of water (as well as carbonates; see below). Its dissolution in water is strongly exothermic, meaning the process gives off significant heat. Concentrated aqueous solutions are sometimes called potassium lyes. Even at high temperatures, solid KOH does not dehydrate readily. Other info is:-
Physical Properties
1. Molecular formula KOH
2. Molar mass 56.1056 g/mol
3. Appearance white solid, deliquescent
4. Odor Odorless
5. Density 2.044 g/cm3
6. Melting point 406 °C, 679 K, 763 °F
7. Boiling point 1327 °C, 1600 K, 2421 °F
8. Solubility in water 97 g/100 mL (0 °C)
121 g/100 mL (25 °C)
178 g/100 mL (100 °C)
9. Solubility soluble in alcohol, glycerol insoluble in ether, liquid ammonia
10. Acidity (pKa) 13.5 (0.1 M)
11. Refractive index (nD) 1.409
12. Crystal structure rhombohedral
Structure
At higher temperatures, solid KOH crystallizes in the NaCl crystal structure. The OH group is either rapidly or randomly disordered so that the OH− group is effectively a spherical anion of radius 1.53 Å (between Cl− and F−