كلوريد الپوتاسيوم

كلوريد الپوتاسيوم
Potassium chloride.jpg
Potassium-chloride-3D-ionic.png
الأسماء
أسماء أخرى
Sylvite
Muriate of potash
المُعرِّفات
رقم CAS
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.028.374 Edit this at Wikidata
E number E508 (acidity regulators, ...)
KEGG
رقم RTECS
  • TS8050000
UNII
الخصائص
الصيغة الجزيئية KCl
كتلة مولية 74.555 g·mol−1
المظهر white crystalline solid
الرائحة odorless
الكثافة 1.984 g/cm3
نقطة الانصهار
نقطة الغليان
قابلية الذوبان في الماء 27.77 g/100mL (0 °C)
33.97 g/100mL (20 °C)
54.02 g/100mL (100 °C)
قابلية الذوبان Soluble in glycerol, alkalies
Slightly soluble in alcohol Insoluble in ether[1]
قابلية الذوبان في ethanol 0.288 g/L (25 °C)[2]
الحموضة (pKa) ~7
القابلية المغناطيسية −39.0·10−6 cm3/mol
معامل الانكسار (nD) 1.4902 (589 nm)
البنية
البنية البلورية face centered cubic
الزمرة الفراغية Fm3m, No. 225
ثابت العقد a = 629.2 pm[3]
هندسة
إحداثية
Octahedral (K+)
Octahedral (Cl)
الكيمياء الحرارية
الإنتالپية المعيارية
للتشكل
ΔfHo298
−436 kJ·mol−1[4]
Standard molar
entropy
So298
83 J·mol−1·K−1[4]
علم الأدوية
A12BA01 (WHO) B05XA01
طرق
التناول
Oral, IV, IM
الحركية الدوائية:
المخاطر
صفحة بيانات السلامة ICSC 1450
NFPA 704 (معيـَّن النار)
Flammability code 0: لن يشتعل. مثل الماءHealth code 1: التعرض سيتسبب في تهيجاً ولكن لا يترك سوى جروح طفيفة باقية. مثل زيت الترپنتينReactivity code 0: مستقر في العادة، حتى تحت ظروف التعرض للنار، ولا يتفاعل مع الماء. مثل النيتروجين السائلSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
0
نقطة الوميض Non-flammable
الجرعة أو التركيز القاتل (LD, LC):
2600 mg/kg (oral, rat)[6]
مركبات ذا علاقة
Potassium fluoride
Potassium bromide
Potassium iodide
Lithium chloride
Sodium chloride
Rubidium chloride
Caesium chloride
Ammonium chloride
مركـّبات ذات علاقة
Potassium chlorate
Potassium perchlorate
ما لم يُذكر غير ذلك، البيانات المعطاة للمواد في حالاتهم العيارية (عند 25 °س [77 °ف]، 100 kPa).
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مراجع الجدول

كلوريد البوتاسيوم هو مركب كيميائي بالصيغة الكيميائية KCl. يكون عديم الرائحة في حالته النقية. بلورته بيضاء أو عديمة اللون ذات بريق زجاجي. تركيبه البلوري ينكسر بسهولة إلى ثلاثة إتجاهات. The solid dissolves readily in water, and its solutions have a salt-like taste. Potassium chloride can be obtained from ancient dried lake deposits.[7] KCl is used as a fertilizer,[8] in medicine, in scientific applications, domestic water softeners (as a substitute for sodium chloride salt), and in food processing, where it may be known as E number additive E508.

It occurs naturally as the mineral sylvite, and in combination with sodium chloride as sylvinite.[9]

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الاستعمالات

سماد

يستعمل مركب كلوريد البوتاسيوم كسماد زراعي يسمى پوتاش، إذ أن نمو العديد من النباتات يحده وفرة البوتاسيوم. Potassium chloride sold as fertilizer is known as muriate of potash (MOP). The vast majority of potash fertilizer worldwide is sold as MOP.

كلوريد البوتاسيوم، المدموك، بتركيز سماد.

الاستخدامات الطبية

Potassium is vital in the human body, and potassium chloride by mouth is the common means to treat low blood potassium, although it can also be given intravenously. It is on the World Health Organization's List of Essential Medicines.[10] Overdose causes hyperkalemia which can disrupt cell signaling to the extent that the heart will stop, reversibly in the case of some open heart surgeries.

الاستخدام في الطهي

It can be used as a salt substitute for food, but due to its weak, bitter, unsalty flavor, it is often mixed with ordinary table salt (sodium chloride) to improve the taste to form low sodium salt. The addition of 1 ppm of thaumatin considerably reduces this bitterness.[11] Complaints of bitterness or a chemical or metallic taste are also reported with potassium chloride used in food.[12]

الصناعية

As a chemical feedstock, it is used for the manufacture of potassium hydroxide and potassium metal. It is also used in medicine, lethal injections, scientific applications, food processing, soaps, and as a sodium-free substitute for table salt for people concerned about the health effects of sodium.

It is used as a supplement in animal feed to boost the potassium level in the feed. As an added benefit, it is known to increase milk production.

It is sometimes used in solution as a completion fluid in petroleum and natural gas operations, as well as being an alternative to sodium chloride in household water softener units.

Glass manufacturers use granular potash as a flux, lowering the temperature at which a mixture melts. Because potash imparts excellent clarity to glass, it is commonly used in eyeglasses, glassware, televisions, and computer monitors.

KCl is useful as a beta radiation source for calibration of radiation monitoring equipment, because natural potassium contains 0.0118% of the isotope 40K. One kilogram of KCl yields 16350 becquerels of radiation, consisting of 89.28% beta and 10.72% gamma, with 1.46083 MeV. In order to use off-the-shelf materials, it needs to be crystallized sequentially, using controlled temperature, in order to extract KCl, which is the subject of ongoing research. It also emits a relatively low level of 511 keV gamma rays from positron annihilation, which can be used to calibrate medical scanners.

Potassium chloride is used in some de-icing products designed to be safer for pets and plants, though these are inferior in melting quality to calcium chloride [lowest usable temperature 12 °F (−11 °C) v. −25 °F (−32 °C)]. It is also used in various brands of bottled water.

Potassium chloride was once used as a fire extinguishing agent, and in portable and wheeled fire extinguishers. Known as Super-K dry chemical, it was more effective than sodium bicarbonate-based dry chemicals and was compatible with protein foam. This agent fell out of favor with the introduction of potassium bicarbonate (Purple-K) dry chemical in the late 1960s, which was much less corrosive, as well as more effective. It is rated for B and C fires.

Along with sodium chloride and lithium chloride, potassium chloride is used as a flux for the gas welding of aluminium.

Potassium chloride is also an optical crystal with a wide transmission range from 210 nm to 20 µm. While cheap, KCl crystals are hygroscopic. This limits its application to protected environments or short-term uses such as prototyping. Exposed to free air, KCl optics will "rot". Whereas KCl components were formerly used for infrared optics, it has been entirely replaced by much tougher crystals such as zinc selenide.

Potassium chloride is used as a scotophor with designation P10 in dark-trace CRTs, e.g. in the Skiatron.

السمية

The typical amounts of potassium chloride found in the diet appear to be generally safe.[13] In larger quantities, however, potassium chloride is toxic. The ج.م.50 of orally ingested potassium chloride is approximately 2.5 g/kg, or 190 grams (6.7 oz) for a body mass of 75 kilograms (165 lb). In comparison, the ج.م.50 of sodium chloride (table salt) is 3.75 g/kg.

Intravenously, the ج.م.50 of potassium chloride is far smaller, at about 57.2 mg/kg to 66.7 mg/kg; this is found by dividing the lethal concentration of positive potassium ions (about 30 to 35 mg/kg)[14] by the proportion by mass of potassium ions in potassium chloride (about 0.52445 mg K+/mg KCl).[15]

الخصائص الكيميائية

  • ينحل مركب كلوريد البوتاسيوم جيدة في الماء، حوالي 34 غ لكل 100 مل ماء عند الدرجة 20°س. في المقابل لا ينحل كلوريد البوتاسيوم عملياً في أغلب المحلات العضوية.
  • المحاليل المائية من مركب كلوريد البوتاسيوم لها صفة معتدلة الأس الهيدروجيني (pH) لها تتراوح ~ 7.
  • يتوافر مركب كلوريد البوتاسيوم طبيعياً في معدن السلفيت Sylvite. كما يوجد أيضاً في معدن الكارناليت، وهو ملح مضاعف من كلوريد البوتاسيوم وكلوريد المغنزيوم كما تشير الصيغة الجزيئية التالية:

KCl . MgCl2 . 6H2O

التحضير

يمكن الحصول على مركب كلوريد البوتاسيوم من معدن الكارناليت الذي يحل بالماء وبإعادة البلورة بشكل حذر لفصله عن الملح المرافق.

قابلية الذوبان

KCl is soluble in a variety of polar solvents.

Solubility[16]
Solvent Solubility
(g/kg of solvent at 25 °C)
Water 360
Liquid ammonia 0.4
Liquid sulfur dioxide 0.41
Methanol 5.3
Ethanol 0.37
Formic acid 192
Sulfolane 0.04
Acetonitrile 0.024
Acetone 0.00091
Formamide 62
Acetamide 24.5
Dimethylformamide 0.17–0.5

Solutions of KCl are common standards, for example for calibration of the electrical conductivity of (ionic) solutions, since KCl solutions are stable, allowing for reproducible measurements. In aqueous solution, it is essentially fully ionized into solvated K+
and Cl
ions.

الاختزال والتحويل إلى فلز البوتاسيوم

Although potassium is more electropositive than sodium, KCl can be reduced to the metal by reaction with metallic sodium at 850 °C because the more volatile potassium can be removed by distillation (see Le Chatelier's principle):

This method is the main method for producing metallic potassium. Electrolysis (used for sodium) fails because of the high solubility of potassium in molten KCl.[9]


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المصادر

  • Taschenbuch chemische Substanzen, Willmes, Verlag Harri Deutsch, ISBN 3-8171-1662-4

المراجع

  1. ^ "Potassium chloride (PIM 430)". International Programme on Chemical Safety. 3.3.1 Properties of the substance. Retrieved 2011-01-17.
  2. ^ "periodic-table-of-elements.org" (website shows values in g/100ml). Retrieved 4 October 2019.
  3. ^ D.B. Sirdeshmukh; L. Sirdeshmukh; K.G. Subhadra. Alkali Halides: A Handbook of Physical Properties.
  4. ^ أ ب Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 978-0-618-94690-7.
  5. ^ "Compound Summary for CID 4873". Pubchem.ncbi.nlm.nih.gov. Retrieved 17 October 2015.
  6. ^ Chambers, Michael. "ChemIDplus - 7447-40-7 - WCUXLLCKKVVCTQ-UHFFFAOYSA-M - Potassium chloride [USP:JAN] - Similar structures search, synonyms, formulas, resource links, and other chemical information". Chem.sis.nlm.nih.gov. Retrieved 22 December 2017.
  7. ^ Rayner-Canham, Geoffrey (22 December 2013). Descriptive inorganic chemistry. Overton, Tina (Sixth ed.). New York, NY. ISBN 978-1-4641-2557-7. OCLC 882867766.{{cite book}}: CS1 maint: location missing publisher (link)
  8. ^ "Potassium Fertilizers (Penn State Agronomy Guide)". Penn State Agronomy Guide (Penn State Extension). Archived from the original on 2016-12-20. Retrieved 2016-12-10.
  9. ^ أ ب Burkhardt, Elizabeth R. (2006). "Potassium and Potassium Alloys". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a22_031.pub2. ISBN 978-3527306732.
  10. ^ World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  11. ^ Lorient, Denis; Linden, G. (1999). New ingredients in food processing: biochemistry and agriculture. Boca Raton: CRC Press. p. 357. ISBN 978-1-85573-443-2. ... in dietary food containing potassium chloride, thaumatin added in the ratio of 1 ppm considerably reduces the sensation of bitterness. ...
  12. ^ Sinopoli, Dominique A.; Lawless, Harry T. (2012). "Taste Properties of Potassium Chloride Alone and in Mixtures with Sodium Chloride Using a Check-All-That-Apply Method". Journal of Food Science. 77 (9): S319–22. doi:10.1111/j.1750-3841.2012.02862.x. PMID 22901084.
  13. ^ Nutrition, Center for Food Safety and Applied. "GRAS Substances (SCOGS) Database - Select Committee on GRAS Substances (SCOGS) Opinion: Potassium chloride". www.fda.gov (in الإنجليزية). Archived from the original on 31 October 2017. Retrieved 21 July 2019.
  14. ^ Bhatkhande, C.Y.; Joglekar, V.D. (1977-01-01). "Fatal poisoning by potassium in human and rabbit". Forensic Science (in الإنجليزية). 9 (1): 33–36. doi:10.1016/0300-9432(77)90062-0. ISSN 0300-9432. PMID 838413.
  15. ^ "Molecular weight of KCl". www.convertunits.com. Retrieved 2018-11-04.
  16. ^ Burgess, J. (1978). Metal Ions in Solution. New York: Ellis Horwood. ISBN 978-0-85312-027-8.[صفحة مطلوبة]
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