Potassium hydroxide is a solid product, which needs to prepare potassium hydroxide solution in some special industries. Preparation of solution is a technical activity, which requires a deep understanding of chemical products and skilled operation of experimental instruments

1、氢氧化钾基准物经干燥处理并恒重，纯度符合要求。

1. After drying and constant weight, the purity of potassium hydroxide reference material meets the requirements.

2、天平须经过检定且处于水平状态。

2. The balance must be calibrated and level.

3、称取的基准物的量要准确，称取0.27—0.33g，称准0.0001g,基准物不能洒落称量瓶或三角烧瓶外，影响重量。

3. The weight of the reference substance should be accurate, weighing 0.27-0.33g to 0.0001g. The reference substance should not fall outside the weighing bottle or triangular flask, affecting the weight.

4、所用蒸馏水须符合GB6682中三级水标准，煮沸10分钟，去除CO2。

4. The distilled water used must meet the third grade water standard in gb6682, and be boiled for 10 minutes to remove CO2.

5、蒸馏水加入80ml，摇动，使其充分溶解。

5. Add 80 ml distilled water and shake to make it dissolve completely.

6、标定过程中所用量筒、三角烧瓶须洁净干燥，量筒、滴定管经检定。

6. The measuring cylinder and triangular flask used in the calibration process shall be clean and dry, and the measuring cylinder and burette shall be verified.

7、所用指示剂要符合要求，为10g/L酚酞指示剂，加入量要准确。

7. The indicator used should meet the requirements, be 10g / L phenolphthalein indicator, and the addition amount should be accurate.

8、滴定管要用待标定氢氧化钾溶液清洗2—3遍，保证溶液的浓度不受影响。

8. The burette should be cleaned with potassium hydroxide solution to be calibrated for 2-3 times to ensure that the concentration of the solution is not affected.

9、溶液装入滴定管中须无气泡，否则影响读数体积，手不得拿滴定管有液体位置，以免由于手温影响体积。

9. There must be no bubbles when the solution is put into the burette, otherwise the reading volume will be affected. Do not hold the burette with liquid position, so as not to affect the volume due to hand temperature.

10、零位调整或滴定后读数须等待30—45s?，且滴定管应垂直，视线与滴定管内液面处于同一水平位置，读数要准确。

10. Wait 30-45s after zero adjustment or titration?, And the burette should be vertical, the line of sight and the liquid level in the burette should be in the same horizontal position, and the reading should be accurate.

11、终点颜色判断须准确，同时作空白试验，系统误差。

11. At the same time, the blank test should be done to eliminate the systematic error.

12、滴定完毕，根据计算公式CKOH=m/［（V1-V0）*0.2042］进行计算，少取三次标定结果的算术平均值作为标准滴定溶液的实际浓度，浓度值取四位有效数字。

12. After titration, calculate according to the calculation formula ckoh = m / [(v1-v0) * 0.2042], take the arithmetic mean of at least three calibration results as the actual concentration of standard titration solution, and take four significant figures as the concentration value.

氢氧化钾标准溶液配制后需要进行反复测量，浓度的变化对产品的性能有很大影响，因此要格外注意。

Potassium hydroxide standard solution needs to be measured repeatedly after preparation. The change of concentration has a great influence on the performance of the product, so special attention should be paid to it.