Potassium hydroxide is a chemical substance, a strong caustic alkali, generally in the form of flakes or particles, soluble in water, and corrosive to sodium carbonate at high temperature. Disproportionation reactions occur with halogens such as chlorine, bromine and iodine, and neutralize with acids to form salt and water. It is known that potassium hydroxide is a white translucent crystalline solid with astringent and slippery taste in its aqueous solution. Potassium hydroxide is one of the important raw materials for the production of polycarbonate, super absorbent polymer, zeolite, epoxy resin, sodium phosphate, sodium sulfite and large amount of sodium salt. But because its own characteristics are easy to deteriorate, how do you know how to detect its deterioration? Next, I'll give you a detailed explanation.

　　NaOH變質(zhì)后會(huì)生成Na?CO?

　　NaOH metamorphoses into Na? CO?

　　化學(xué)方程式：2NaOH+CO?=Na?CO?+H?O

　　Chemical equation: 2Na O H+CO?=Na?CO?+H?O?

　　一、樣品中滴加澄清石灰水，若有白色沉淀生成，則氫氧化鉀變質(zhì)。

　　1. The sample is dripped with clarified limewater. If white precipitation occurs, potassium hydroxide will deteriorate.

　　原理：Na?CO?+Ca(OH)?=CaCO?↓+2NaOH

　　Principle: Na?CO?+Ca(OH)?= CaCO?+2NaOH

　　二、樣品中滴加過(guò)量稀鹽酸若有氣泡產(chǎn)生，則氫氧化鉀變質(zhì)。

　　2. Potassium hydroxide deteriorates when excessive dilute hydrochloric acid is added to the sample and bubbles are formed.

　　原理：2HCl+Na?CO?=2NaCl+CO?↑+H?O

　　Principle: 2HCl+Na?CO?= 2NaCl+CO?+H?O?

　?。諝庵泻猩倭康腃O?，而敞口放置的NaOH溶液能夠與CO?反應(yīng)，生成Na?CO?和H?O從而變質(zhì)；HCl中的H+能夠與Na?CO?中的CO32-離子反應(yīng)生成CO?氣體和H?O，通過(guò)氣泡產(chǎn)生這個(gè)現(xiàn)象來(lái)檢驗(yàn)變質(zhì)）

　　(There is a small amount of CO in the air, and the open Na O H solution can react with CO? To produce Na? CO? And H? O, which can deteriorate; H + in HCl can react with CO32 - ions in Na? CO? To produce CO? Gas and H? O, which can be detected by bubble formation.)

　　注：HCl會(huì)優(yōu)先與NaOH反應(yīng)生成NaCl和H?O。因?yàn)镹aOH是強(qiáng)堿，而Na?CO?是水溶液顯堿性。

　　Note: HCl reacts preferentially with NaOH to produce NaCl and H?O. Because NaOH is strong base, and Na? CO? Is alkaline in aqueous solution.

　　三、樣品中加氯化鋇，若有白色沉淀生成，則氫氧化鉀變質(zhì)。

　　3. If barium chloride is added to the sample and white precipitation is formed, potassium hydroxide will deteriorate.

　　原理：Na?CO?+BaCl?=BaCO?↓+2NaCl

　　Principle: Na? CO?+BaCl?= BaCO?+2NaCl

　　四、檢驗(yàn)氫氧化鉀部分變質(zhì)：

　　IV. Inspection of partial deterioration of potassium hydroxide:

　　1、加入過(guò)量BaCl?或Ba（NO?）2完全沉淀，證明有Na?CO?產(chǎn)生，待沉淀完全靜止后，取上層清液于試管內(nèi)，滴加無(wú)色酚酞溶液，酚酞變紅，則證明有NaOH。

　　1. Adding excessive BaCl? Or Ba (NO?) 2 to complete precipitation proves that Na? CO? Is produced. When the precipitation is completely stationary, the supernatant is taken into the test tube, and the colorless phenolphthalein solution is dripped, and the phenolphthalein turns red, which proves that NaOH exists.

　　注：不滴加NH?Cl，因?yàn)镹a?CO?溶于水后呈堿性是因?yàn)闀?huì)有OHˉ根離子，NH?+與OHˉ跟結(jié)合也會(huì)有刺激性氣味，無(wú)法區(qū)分是原有氫氧化鉀導(dǎo)致還是碳酸鈉導(dǎo)致。

　　Note: No NH? Cl is added, because Na? CO? Is alkaline after dissolving in water because of the presence of OH radical ions, and the combination of NH?+ and OH also has a stimulating odor. It is impossible to distinguish between the original potassium hydroxide or sodium carbonate.

　　2、在NaOH中加入過(guò)量CaCl2：1.若有白色沉淀生成，則說(shuō)明NaOH變質(zhì)2.加入無(wú)色酚酞，若無(wú)色酚酞不變色，則說(shuō)明完全變質(zhì)。若無(wú)色酚酞變紅，說(shuō)明部分變質(zhì)。

　　2. Adding excessive CaCl2:1 to NaOH. If white precipitation is formed, NaOH will deteriorate. 2. Adding colorless phenolphthalein, if colorless phenolphthalein does not change, it will completely deteriorate. If the colorless phenolphthalein turns red, it indicates partial deterioration.

　　大家在了解了上述關(guān)于氫氧化鉀的變質(zhì)檢測(cè)方法，對(duì)于這種成份大家可以作為了解避免錯(cuò)誤的使用會(huì)帶來(lái)很大的影響，對(duì)于氫氧化鉀如果大家想要了解更多的咨詢可以咨詢我們，希望大家能學(xué)會(huì)并且可以嘗試檢測(cè)一下?？梢杂糜凇Ｓ糜谠旒?、肥皂、染料、人造絲、制鋁、石油精制等等行業(yè)。

　　We are all aware of the above deterioration detection methods for potassium hydroxide, which can be used as an understanding of how to avoid the wrong use of potassium hydroxide will have a great impact. For potassium hydroxide, if you want to know more about the consultation, you can consult us, I hope you may learn and try to test it. It can be used. Used in papermaking, soap, dyes, rayon, aluminium, petroleum refining and other industries.