氢氧化钾外观为白色片状或粉状，具有强烈腐蚀性和强碱性。氢氧化钾溶液外观则为无色透明状溶液。氢氧化钾暴露在空气中时，极易被空气中的水分而潮解，并吸收二氧化碳而成碳酸钾。氢氧化钾易溶于水、乙醇或酸时，会释放大量的热量。氢氧化钾溶液化学式为KOH，分子量为56.1，沸点为1324℃，熔点为360.4℃，相对密度(水=1)为2.04。0.1mol/L溶液的pH为13.5。
The appearance of potassium hydroxide is white flake or powder, with strong corrosivity and strong alkalinity. The appearance of potassium hydroxide solution is colorless and transparent. When potassium hydroxide is exposed to the air, it is easily deliquescent by water in the air and absorbs carbon dioxide to form potassium carbonate. When potassium hydroxide is easily soluble in water, ethanol or acid, it will release a lot of heat. The chemical formula of potassium hydroxide solution is Koh, the molecular weight is 56.1, the boiling point is 1324 ℃, the melting point is 360.4 ℃, and the relative density (water = 1) is 2.04. The pH of 0.1mol/l solution is 13.5.
氢氧化钾主要被用于干燥剂、吸收剂。还用于电镀、雕刻、石印术等。在纺织工业中，用于印染和漂白作用，并大量用作制造人造纤维、聚酯纤维的主要原料。
Potassium hydroxide is mainly used as desiccant and absorbent. It is also used for electroplating, engraving, lithography, etc. In the textile industry, it is used for printing and dyeing and bleaching, and is widely used as the main raw material for manufacturing man-made fiber and polyester fiber.

氢氧化钠俗称片碱，外观为白色半透明状的固体，具有强腐蚀性的强碱。氢氧化钠溶于水时会形成碱性溶液，其水溶液没有吸水性，但能与酸发生反应并放热，可能会产生有毒性烟雾。氢氧化钠相对密度2.130；熔点318.4℃；沸点1390℃。氢氧化钠的质量标准分别有含量为99片碱和96片碱。
Sodium hydroxide, commonly known as flake alkali, is a white translucent solid with strong corrosivity. When sodium hydroxide is dissolved in water, it will form an alkaline solution. Its aqueous solution has no water absorption, but can react with acid and release heat, which may produce toxic smoke. The relative density of sodium hydroxide is 2.130; Melting point 318.4 ℃; Boiling point 1390 ℃. The quality standards of sodium hydroxide are 99 flakes of alkali and 96 flakes of alkali respectively.
氢氧化钠广泛用于粘胶纤维、人造丝及绵织品等轻纺工业方面，农药、染料、橡胶和化学工业方面、石油钻探，精炼石油油脂和提炼焦油的石油工业。
Sodium hydroxide is widely used in light textile industry such as viscose fiber, rayon and cotton fabric, pesticide, dye, rubber and chemical industry, oil drilling, petroleum oil refining and tar refining.
氢氧化钾溶液的吸湿性比氢氧化钠强，所以常用氢氧化钾做干燥剂。
Potassium hydroxide solution is more hygroscopic than sodium hydroxide, so potassium hydroxide is often used as desiccant.