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

2、稱取氫氧化鉀和水，可用天平等相關儀器精確稱取。

2. Weigh potassium hydroxide and water accurately with balance and other relevant instruments.

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 potassium hydroxide into water and slowly stir with a glass until it is uniform.

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 first, put it into the oven and dry it until the working reference reagent potassium hydrogen phthalate is dissolved in water without carbon dioxide, and use phenolphthalein reagent for calibration. Calibration before use.

氫氧化鉀標準滴定溶液的濃度，數值以摩爾每升表示，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量的準確數值，單位為克（g）；

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

V1——氫氧化鉀-乙醇溶液的體積的數值，單位為毫升（ml）；

V1 -- volume 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值，單位為毫升（ml）；

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

M——鄰苯二甲酸氫鉀的摩爾質量的數值，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]