The chemical formula of KOH is white powder or flake solid. Its melting point is 380 ℃, and its boiling point is 1324 ℃. It has the characteristics of strong alkali and corrosiveness. When exposed to the air, it is easy to absorb water in the air and deliquesce, and absorb carbon dioxide to form potassium carbonate. Soluble in water, ethanol and glycerin. When dissolved in water, alcohol or treated with acid, a lot of heat will be generated.

　　以下是30%氫氧化鉀溶液配置方法：

　　The following is the preparation method of 30% potassium hydroxide solution:

　　1、計算氫氧化鉀和水的比例：這里以30%氫氧化鉀溶液為例，那么則需要氫氧化鉀30g，水80g。

　　1. Calculate the proportion of potassium hydroxide and water: take 30% potassium hydroxide solution as an example, then 30 g of potassium hydroxide and 80 g of water are needed.

　　2、稱取氫氧化鉀和水，可用天平等相關(guān)儀器精確稱取。

　　2. Weigh potassium hydroxide and water, and use balance and other relevant instruments to weigh accurately.

　　3、將氫氧化鉀緩慢的倒入水中，用玻璃杯緩慢攪拌，直均勻。

　　3. Slowly pour the potassium hydroxide into the water and stir with a glass until it is even.

　　4、標定：一般先稱取定量溶液放入烘箱中烘干工作基準試劑鄰苯二甲酸氫鉀，再溶于無二氧化碳的水中，使用酚酞試劑進行標定。臨用前標定。

　　4. Calibration: generally, weigh the quantitative solution and dry it in the oven to the working reference reagent potassium hydrogen phthalate, then dissolve it in the water without carbon dioxide, and calibrate it with phenolphthalein reagent. Pre use calibration.

　　氫氧化鉀標準滴定溶液的濃度，數(shù)值以摩爾每升表示，按以下公式計算：

　　The concentration of potassium hydroxide standard titration solution, expressed in moles per liter, is calculated according to the following formula:

　　其中，m——鄰苯二甲酸氫鉀的質(zhì)量的準確數(shù)值，單位為克（g）；

　　Where, m -- the accurate value of the mass of potassium hydrogen phthalate, unit: G;

　　V1——氫氧化鉀-乙醇溶液的體積的數(shù)值，單位為毫升（ml）；

　　V1 -- volume value of potassium hydroxide ethanol solution, unit: ml;

　　V2——空白試驗氫氧化鉀-乙醇溶液的體積的數(shù)值，單位為毫升（ml）；

　　V2 -- volume value of blank test potassium hydroxide ethanol solution, unit: ml;

　　M——鄰苯二甲酸氫鉀的摩爾質(zhì)量的數(shù)值，單位為克每摩爾（g/mol）[M(KHC8H4O4)=204.22]

　　M -- value of molar mass of potassium hydrogen phthalate, unit: g / mol [M (khc8h4o4) = 204.22]