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.

氫氧化鉀主要被用于干燥劑、吸收劑。還用于電鍍、雕刻、石印術等。在紡織工業中，用于印染和漂白作用，并大量用作制造人造纖維、聚酯纖維的主要原料。

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.

氫氧化鈉俗稱片堿，外觀為白色半透明狀的固體，具有強腐蝕性的強堿。氫氧化鈉溶于水時會形成堿性溶液，其水溶液沒有吸水性，但能與酸發生反應并放熱，可能會產生有毒性煙霧。氫氧化鈉相對密度2.130；熔點318.4℃；沸點1390℃。氫氧化鈉的質量標準分別有含量為99片堿和96片堿。

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.

氫氧化鈉廣泛用于粘膠纖維、人造絲及綿織品等輕紡工業方面，農藥、染料、橡膠和化學工業方面、石油鉆探，精煉石油油脂和提煉焦油的石油工業。

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.

氫氧化鉀溶液的吸濕性比氫氧化鈉強，所以常用氫氧化鉀做干燥劑。

Potassium hydroxide solution is more hygroscopic than sodium hydroxide, so potassium hydroxide is often used as desiccant.