Potassium/ja: Difference between revisions

KOH is a [[strong base]]. Illustrating its [[hydrophilic]] character, as much as 1.21 [[kilogram|kg]] of KOH can dissolve in a single liter of water. Anhydrous KOH is rarely encountered. KOH reacts readily with [[carbon dioxide]] ({{chem2|CO2}}) to produce [[potassium carbonate]] ({{chem2|K2CO3}}), and in principle could be used to remove traces of the gas from air. Like the closely related [[sodium hydroxide]], KOH reacts with [[fat]]s to produce [[soap]]s.

In general, potassium compounds are ionic and, owing to the high hydration energy of the {{chem2|K+}} ion, have excellent water solubility. The main species in water solution are the [[Metal aquo complex|aquo complexes]] {{chem2|[K(H2O)_{''n''}]+}} where ''n'' = 6 and 7.

[[Potassium heptafluorotantalate]] ({{chem2|K2[TaF7]}}) is an intermediate in the purification of [[tantalum]] from the otherwise persistent contaminant of [[niobium]].

[[Organopotassium compound]]s illustrate nonionic compounds of potassium. They feature highly [[Chemical polarity|polar]] [[covalent]] K–C bonds. Examples include [[benzyl potassium]] {{chem2|KCH2C6H5}}. Potassium [[Intercalation (chemistry)|intercalate]]s into [[graphite]] to give a variety of [[graphite intercalation compounds]], including {{chem2|KC8}}.

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===Isotopes===

{{main|Isotopes of potassium}}

There are 25 known [[isotope]]s of potassium, three of which occur naturally: {{chem|39|K}} (93.3%), {{chem|40|K}} (0.0117%), and {{chem|41|K}} (6.7%) (by mole fraction). Naturally occurring [[potassium-40|{{chem|40|K}}]] has a [[half-life]] of {{val|1.250e9}} years. It decays to stable [[Argon|{{chem|40|Ar}}]] by [[electron capture]] or [[positron emission]] (11.2%) or to stable [[Calcium|{{chem|40|Ca}}]] by [[beta decay]] (88.8%). The decay of {{chem|40|K}} to {{chem|40|Ar}} is the basis of a common method for dating rocks. The conventional [[Potassium-argon dating|K-Ar dating method]] depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon ({{chem|40|Ar}}) was quantitatively retained. [[Mineral]]s are dated by measurement of the concentration of potassium and the amount of radiogenic {{chem|40|Ar}} that has accumulated. The minerals best suited for dating include [[biotite]], [[muscovite]], [[metamorphic]] [[hornblende]], and volcanic [[feldspar]]; [[Petrography|whole rock]] samples from volcanic flows and shallow [[Igneous rock|instrusives]] can also be dated if they are unaltered. Apart from dating, potassium isotopes have been used as [[radioactive tracer|tracers]] in studies of [[weathering]] and for [[nutrient cycling]] studies because potassium is a [[macronutrient (ecology)|macronutrient]] required for [[life]] on Earth.

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{{chem|40|K}} occurs in natural potassium (and thus in some commercial salt substitutes) in sufficient quantity that large bags of those substitutes can be used as a radioactive source for classroom demonstrations. {{chem|40|K}} is the radioisotope with the largest abundance [[Composition of the human body|in the human body]]. In healthy animals and people, {{chem|40|K}} represents the largest source of radioactivity, greater even than [[Carbon-14|{{chem|14|C}}]]. In a human body of 70 kg, about 4,400 nuclei of {{chem|40|K}} decay per second. The activity of natural potassium is 31 [[Becquerel|Bq]]/g.

==History==

===Potash===

{{main|Potash}}

Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition was not understood. [[Georg Ernst Stahl]] obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus [[Antoine Lavoisier]] did not include the alkali in his list of chemical elements in 1789. For a long time the only significant applications for potash were the production of glass, bleach, soap and [[gunpowder]] as potassium nitrate. Potassium soaps from animal fats and vegetable oils were especially prized because they tend to be more water-soluble and of softer texture, and are therefore known as soft soaps. The discovery by [[Justus Liebig]] in 1840 that potassium is a necessary element for plants and that most types of soil lack potassium caused a steep rise in demand for potassium salts. Wood-ash from fir trees was initially used as a potassium salt source for fertilizer, but, with the discovery in 1868 of mineral deposits containing [[potassium chloride]] near [[Staßfurt]], Germany, the production of potassium-containing fertilizers began at an industrial scale. Other potash deposits were discovered, and by the 1960s Canada became the dominant producer.

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===Metal===

[[File:Sir Humphry Davy, Bt by Thomas Phillips.jpg|thumb|[[Humphry Davy|Sir Humphry Davy]] ]]

[[File:Potassium.JPG|thumb|upright|left|Pieces of potassium metal]]

Potassium ''metal'' was first isolated in 1807 by Humphry Davy, who derived it by electrolysis of molten [[caustic potash]] (KOH) with the newly discovered [[voltaic pile]]. Potassium was the first metal that was isolated by electrolysis. Later in the same year, Davy reported extraction of the metal [[sodium]] from a mineral derivative ([[caustic soda]], NaOH, or lye) rather than a plant salt, by a similar technique, demonstrating that the elements, and thus the salts, are different. Although the production of potassium and sodium metal should have shown that both are elements, it took some time before this view was universally accepted.

Because of the sensitivity of potassium to water and air, [[air-free technique]]s are normally employed for handling the element. It is unreactive toward nitrogen and saturated hydrocarbons such as mineral oil or [[kerosene]]. It readily dissolves in liquid [[ammonia]], up to 480 g per 1000 g of ammonia at 0{{nbsp}}°C. Depending on the concentration, the ammonia solutions are blue to yellow, and their electrical conductivity is similar to that of liquid metals. Potassium slowly reacts with ammonia to form [[Potassium amide|{{chem|KNH|2}}]], but this reaction is accelerated by minute amounts of transition metal salts. Because it can reduce the [[salts]] to the metal, potassium is often used as the reductant in the preparation of finely divided metals from their salts by the [[Rieke metal|Rieke method]]. Illustrative is the preparation of magnesium:

:{{chem2|[[Magnesium chloride|MgCl2]] + 2 K → Mg + 2 KCl}}

==Occurrence==

[[File:PotassiumFeldsparUSGOV.jpg|thumb|left|upright|Potassium in [[feldspar]]]]

Potassium is formed in [[supernova]]e by [[nucleosynthesis]] from lighter atoms. Potassium is principally created in Type II supernovae via an [[Supernova nucleosynthesis|explosive oxygen-burning process]]. These are nuclear [[Nuclear_Fusion|fusion]] reactions, not to be confused with chemical burning of potassium in oxygen. {{chem|40|K}} is also formed in {{Nowrap|[[s-process]]}} nucleosynthesis and the [[neon burning process]].

Potassium is the 20th most abundant element in the solar system and the 17th most abundant element by weight in the Earth. It makes up about 2.6% of the weight of the [[Earth's crust]] and is the seventh most abundant element in the crust. The potassium concentration in seawater is 0.39{{nbsp}}g/L (0.039 wt/v%), about one twenty-seventh the concentration of sodium.

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===Geology===

Elemental potassium does not occur in nature because of its high reactivity. It reacts violently with water and also reacts with oxygen. [[Orthoclase]] (potassium feldspar) is a common rock-forming mineral. [[Granite]] for example contains 5% potassium, which is well above the average in the Earth's crust. [[Sylvite]] (KCl), [[carnallite]] ({{chem2|KCl*MgCl2*6H2O}}), [[kainite]] ({{chem2|MgSO4*KCl*3H2O}}) and [[langbeinite]] ({{chem2|MgSO4*K2SO4}}) are the minerals found in large [[evaporite]] deposits worldwide. The deposits often show layers starting with the least soluble at the bottom and the most soluble on top. Deposits of niter ([[potassium nitrate]]) are formed by decomposition of organic material in contact with atmosphere, mostly in caves; because of the good water solubility of niter the formation of larger deposits requires special environmental conditions.

==Commercial production==

===Mining===

[[File:Museo de La Plata - Silvita.jpg|thumb|left| [[Sylvite]] from New Mexico]]

[[File:Wintershall Monte Kali 12.jpg|thumb|[[Monte Kali (Heringen)|Monte Kali]], a potash mining and [[beneficiation]] waste heap in [[Hesse|Hesse, Germany]], consisting mostly of [[sodium chloride]].]]

Potassium salts such as [[carnallite]], [[langbeinite]], [[polyhalite]], and [[sylvite]] form extensive [[evaporite]] deposits in ancient lake bottoms and [[seabed]]s, making extraction of potassium salts in these environments commercially viable. The principal source of potassium – potash – is mined in [[Canada]], [[Russia]], [[Belarus]], [[Kazakhstan]], [[Germany]], [[Israel]], the U.S., [[Jordan]], and other places around the world. The first mined deposits were located near Staßfurt, Germany, but the deposits span from [[Great Britain]] over Germany into Poland. They are located in the [[Zechstein]] and were deposited in the Middle to Late [[Permian]]. The largest deposits ever found lie {{convert|1000|m|ft|abbr=off|sp=us}} below the surface of the Canadian province of [[Saskatchewan]]. The deposits are located in the [[Elk Point Group]] produced in the [[Middle Devonian]]. Saskatchewan, where several large mines have operated since the 1960s pioneered the technique of freezing of wet sands (the Blairmore formation) to drive mine shafts through them. The main potash mining company in Saskatchewan until its merge was the [[Potash Corporation of Saskatchewan]], now [[Nutrien]]. The water of the [[Dead Sea]] is used by Israel and Jordan as a source of potash, while the concentration in normal oceans is too low for commercial production at current prices.

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===Chemical extraction===

Several methods are used to separate potassium salts from sodium and magnesium compounds. The most-used method is fractional precipitation using the solubility differences of the salts. Electrostatic separation of the ground salt mixture is also used in some mines. The resulting sodium and magnesium waste is either stored underground or piled up in [[slag heap]]s. Most of the mined potassium mineral ends up as potassium chloride after processing. The mineral industry refers to potassium chloride either as potash, muriate of potash, or simply MOP.

Pure potassium metal can be isolated by electrolysis of its [[potassium hydroxide|hydroxide]] in a process that has changed little since it was first used by Humphry Davy in 1807. Although the electrolysis process was developed and used in industrial scale in the 1920s, the thermal method by reacting sodium with [[potassium chloride]] in a chemical equilibrium reaction became the dominant method in the 1950s.

The production of [[NaK|sodium potassium alloys]] is accomplished by changing the reaction time and the amount of sodium used in the reaction. The Griesheimer process employing the reaction of [[potassium fluoride]] with [[calcium carbide]] was also used to produce potassium.

[[reagent|Reagent-grade]] potassium metal costs about $10.00/[[pound (mass)|pound]] ($22/[[kg]]) in 2010 when purchased by the [[tonne]]. Lower purity metal is considerably cheaper. The market is volatile because long-term storage of the metal is difficult. It must be stored in a dry [[inert gas]] atmosphere or [[anhydrous]] [[mineral oil]] to prevent the formation of a surface layer of [[potassium superoxide]], a pressure-sensitive [[explosive]] that [[Detonation|detonates]] when scratched. The resulting explosion often starts a fire difficult to extinguish.

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===Cation identification===

Potassium is now quantified by ionization techniques, but at one time it was quantitated by [[gravimetric analysis]].

Reagents used to precipitate potassium salts include [[sodium tetraphenylborate]], [[hexachloroplatinic acid]], and [[sodium cobaltinitrite]] into respectively [[potassium tetraphenylborate]], [[potassium hexachloroplatinate]], and [[potassium cobaltinitrite]].

The reaction with [[sodium cobaltinitrite]] is illustrative:

==Commercial uses==

===Fertilizer===

[[File:Patentkali (Potassium sulfate with magnesium).jpg|thumb|Potassium sulfate/magnesium sulfate fertilizer]]

Potassium ions are an essential component of [[plant]] nutrition and are found in most [[soil]] types. They are used as a [[fertilizer]] in [[agriculture]], [[horticulture]], and [[hydroponic]] culture in the form of [[potassium chloride|chloride]] (KCl), [[potassium sulfate|sulfate]] ({{chem2|K2SO4}}), or [[potassium nitrate|nitrate]] ({{chem2|KNO3}}), representing the 'K' [[labeling of fertilizer|in 'NPK']]. Agricultural fertilizers consume 95% of global potassium chemical production, and about 90% of this potassium is supplied as KCl. The potassium content of most plants ranges from 0.5% to 2% of the harvested weight of crops, conventionally expressed as amount of {{chem2|K2O}}. Modern high-[[Crop yield|yield]] agriculture depends upon fertilizers to replace the potassium lost at harvest. Most agricultural fertilizers contain potassium chloride, while potassium sulfate is used for chloride-sensitive crops or crops needing higher sulfur content. The sulfate is produced mostly by decomposition of the complex minerals [[kainite]] ({{chem2|MgSO4*KCl*3H2O}}) and [[langbeinite]] ({{chem2|MgSO4*K2SO4}}). Only a very few fertilizers contain potassium nitrate. In 2005, about 93% of world potassium production was consumed by the fertilizer industry. Furthermore, potassium can play a key role in nutrient cycling by controlling litter composition.

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===Medical use===

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====Potassium citrate====

[[Potassium citrate]] is used to treat a [[kidney stone]] condition called [[renal tubular acidosis]].

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====Potassium chloride====

{{see also|Potassium chloride (medical use)}}

Potassium, in the form of potassium chloride is used as a medication to treat and prevent [[low blood potassium]]. Low blood potassium may occur due to [[vomiting]], [[diarrhea]], or certain medications. It is given by [[intravenous infusion|slow injection into a vein]] or by mouth.

===Food additives===

Potassium sodium tartrate ({{chem2|KNaC4H4O6}}, [[Rochelle salt]]) is a main constituent of some varieties of [[baking powder]]; it is also used in the [[silvering]] of mirrors. [[Potassium bromate]] ({{chem2|KBrO3}}) is a strong oxidizer (E924), used to improve [[dough]] strength and rise height. [[Potassium bisulfite]] ({{chem2|KHSO3}}) is used as a food preservative, for example in [[wine]] and [[beer]]-making (but not in meats). It is also used to [[bleach]] textiles and straw, and in the tanning of [[leather]]s.

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===Industrial===

KOH is a strong base, which is used in industry to neutralize strong and weak [[acid]]s, to control [[pH]] and to manufacture potassium [[salt (chemistry)|salts]]. It is also used to [[saponification|saponify]] fats and [[oils]], in industrial cleaners, and in hydrolysis reactions, for example of [[esters]].

[[Potassium nitrate]] ({{chem2|KNO3}}) or saltpeter is obtained from natural sources such as [[guano]] and [[evaporites]] or manufactured via the [[Haber process]]; it is the [[oxidant]] in gunpowder ([[black powder]]) and an important agricultural fertilizer. [[Potassium cyanide]] (KCN) is used industrially to dissolve [[copper]] and precious metals, in particular [[silver]] and [[gold]], by forming [[complex (chemistry)|complexes]]. Its applications include [[gold mining]], [[electroplating]], and [[electroforming]] of these [[metal]]s; it is also used in [[organic synthesis]] to make [[nitriles]]. Potassium carbonate ({{chem2|K2CO3}} or potash) is used in the manufacture of glass, soap, color TV tubes, fluorescent lamps, textile dyes and pigments. [[Potassium permanganate]] ({{chem2|KMnO4}}) is an oxidizing, bleaching and purification substance and is used for production of [[saccharin]]. [[Potassium chlorate]] ({{chem2|KClO3}}) is added to matches and explosives. [[Potassium bromide]] (KBr) was formerly used as a sedative and in photography.

While [[potassium chromate]] ({{chem2|K2CrO4}}) is used in the manufacture of a host of different commercial products such as [[ink]]s, [[dye]]s, wood [[stain]]s (by reacting with the [[tannic acid]] in wood), [[explosive]]s, [[fireworks]], [[fly paper]], and [[safety match]]es, as well as in the tanning of leather, all of these uses are due to the chemistry of the [[chromate ion]] rather than to that of the potassium ion.

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====Niche uses====

There are thousands of uses of various potassium compounds. One example is [[potassium superoxide]], {{chem2|KO2}}, an orange solid that acts as a portable source of oxygen and a carbon dioxide absorber. It is widely used in [[Rebreather#Rebreathers using an absorbent that releases oxygen|respiration systems]] in mines, submarines and spacecraft as it takes less volume than the gaseous oxygen.

Another example is [[potassium cobaltinitrite]], {{chem2|K3[Co(NO2)6]}}, which is used as artist's pigment under the name of [[Aureolin]] or Cobalt Yellow.

The stable isotopes of potassium can be [[Laser cooling|laser cooled]] and used to probe fundamental and [[Quantum technology|technological]] problems in [[Quantum mechanics|quantum physics]]. The two [[boson]]ic isotopes possess convenient [[Feshbach resonance]]s to enable studies requiring tunable interactions, while {{chem|40|K}} is one of only two stable [[fermion]]s amongst the alkali metals.

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====Laboratory uses====

An [[alloy]] of sodium and potassium, [[NaK]] is a liquid used as a heat-transfer medium and a [[desiccant]] for producing [[air-free technique|dry and air-free solvents]]. It can also be used in [[reactive distillation]]. The ternary alloy of 12% Na, 47% K and 41% Cs has the lowest melting point of −78{{nbsp}}°C of any metallic compound.

Metallic potassium is used in several types of [[magnetometer]]s.

==Biological role==

{{Main|Potassium in biology}}

Potassium is the eighth or ninth most common element by mass (0.2%) in the human body, so that a 60{{nbsp}}kg adult contains a total of about 120{{nbsp}}g of potassium. The body has about as much potassium as sulfur and chlorine, and only calcium and phosphorus are more abundant (with the exception of the ubiquitous [[CHON]] elements).

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===Biochemical function===

*resting cellular-membrane potential and the propagation of action potentials in neuronal, muscular, and cardiac tissue. Due to the electrostatic and chemical properties, {{chem2|K+}} ions are larger than {{chem2|Na+}} ions, and ion channels and pumps in cell membranes can differentiate between the two ions, actively pumping or passively passing one of the two ions while blocking the other.

*hormone secretion and action

*vascular tone

*systemic blood pressure control

*gastrointestinal motility

*acid–base homeostasis

*glucose and insulin metabolism

*mineralocorticoid action

*renal concentrating ability

*fluid and electrolyte balance

*local cortical monoaminergic norepinephrine, serotonin, and dopamine levels, and through them, sleep/wake balance, and spontaneous activity.

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===Homeostasis===

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====Plasma levels====

Plasma potassium is normally kept at 3.5 to 5.5 millimoles (mmol) [or milliequivalents (mEq)] per liter by multiple mechanisms. Levels outside this range are associated with an increasing rate of death from multiple causes, and some cardiac, kidney, and lung diseases progress more rapidly if serum potassium levels are not maintained within the normal range.

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An average meal of 40–50{{nbsp}}mmol presents the body with more potassium than is present in all plasma (20–25{{nbsp}}mmol). This surge causes the plasma potassium to rise up to 10% before clearance by renal and extrarenal mechanisms.

[[Hypokalemia]], a deficiency of potassium in the plasma, can be fatal if severe. Common causes are increased gastrointestinal loss ([[vomiting]], [[diarrhea]]), and increased renal loss ([[polyuria|diuresis]]). Deficiency symptoms include muscle weakness, [[paralytic ileus]], ECG abnormalities, decreased reflex response; and in severe cases, respiratory paralysis, [[alkalosis]], and [[cardiac arrhythmia]].

====Control mechanisms====

# a reactive negative-feedback system,

# a reactive feed-forward system,

# a predictive or [[circadian]] system, and

# an internal or cell membrane transport system.

* The reactive negative-feedback system refers to the system that induces renal secretion of potassium in response to a rise in the plasma potassium (potassium ingestion, shift out of cells, or intravenous infusion.)

* The reactive feed-forward system refers to an incompletely understood system that induces renal potassium secretion in response to potassium ingestion prior to any rise in the plasma potassium. This is probably initiated by gut cell potassium receptors that detect ingested potassium and trigger [[vagal]] [[afferent nerve fiber|afferent]] signals to the pituitary gland.

* The predictive or circadian system increases renal secretion of potassium during mealtime hours (e.g. daytime for humans, nighttime for rodents) independent of the presence, amount, or absence of potassium ingestion. It is mediated by a [[circadian oscillator]] in the [[suprachiasmatic nucleus]] of the brain (central clock), which causes the kidney (peripheral clock) to secrete potassium in this rhythmic circadian fashion.[[File:Scheme sodium-potassium pump-en.svg|thumb|right|upright=1.8|The action of the [[sodium-potassium pump]] is an example of primary [[active transport]]. The two carrier proteins embedded in the cell membrane on the left are using [[Adenosine triphosphate|ATP]] to move sodium out of the cell against the concentration gradient; The two proteins on the right are using secondary active transport to move potassium into the cell. This process results in reconstitution of ATP.]]

* The ion transport system moves potassium across the cell membrane using two mechanisms. One is active and pumps sodium out of, and potassium into, the cell. The other is passive and allows potassium to leak out of the cell. Potassium and sodium cations influence fluid distribution between intracellular and extracellular compartments by [[osmotic]] forces. The movement of potassium and sodium through the cell membrane is mediated by the [[Na⁺/K⁺-ATPase]] pump. This [[Ion transporter|ion pump]] uses [[Adenosine triphosphate|ATP]] to pump three sodium ions out of the cell and two potassium ions into the cell, creating an electrochemical gradient and electromotive force across the cell membrane. The highly selective [[potassium ion channels]] (which are [[tetramer]]s) are crucial for [[Hyperpolarization (biology)|hyperpolarization]] inside [[neuron]]s after an action potential is triggered, to cite one example. The most recently discovered potassium ion channel is KirBac3.1, which makes a total of five potassium ion channels (KcsA, KirBac1.1, KirBac3.1, KvAP, and MthK) with a determined structure. All five are from [[prokaryotic]] species.

====Renal filtration, reabsorption, and excretion====

Renal handling of potassium is closely connected to sodium handling. Potassium is the major cation (positive ion) inside animal cells (150{{nbsp}}mmol/L, 4.8{{nbsp}}g/L), while sodium is the major cation of [[extracellular fluid]] (150{{nbsp}}mmol/L, 3.345{{nbsp}}g/L). In the kidneys, about 180{{nbsp}}liters of plasma is filtered through the [[Glomerulus (kidney)|glomeruli]] and into the [[renal tubules]] per day. This filtering involves about 600{{nbsp}}mg of sodium and 33{{nbsp}}mg of potassium. Since only 1–10{{nbsp}}mg of sodium and 1–4{{nbsp}}mg of potassium are likely to be replaced by diet, renal filtering must efficiently reabsorb the remainder from the plasma.

Sodium is reabsorbed to maintain extracellular volume, osmotic pressure, and serum sodium concentration within narrow limits. Potassium is reabsorbed to maintain serum potassium concentration within narrow limits. [[Sodium pump]]s in the renal tubules operate to reabsorb sodium. Potassium must be conserved, but because the amount of potassium in the blood plasma is very small and the pool of potassium in the cells is about 30 times as large, the situation is not so critical for potassium. Since potassium is moved passively in counter flow to sodium in response to an apparent (but not actual) [[Donnan equilibrium]], the urine can never sink below the concentration of potassium in serum except sometimes by actively excreting water at the end of the processing. Potassium is excreted twice and reabsorbed three times before the urine reaches the collecting tubules. At that point, urine usually has about the same potassium concentration as plasma. At the end of the processing, potassium is secreted one more time if the serum levels are too high.

With no potassium intake, it is excreted at about 200{{nbsp}}mg per day until, in about a week, potassium in the serum declines to a mildly deficient level of 3.0–3.5{{nbsp}}mmol/L. If potassium is still withheld, the concentration continues to fall until a severe deficiency causes eventual death.

The potassium moves passively through pores in the cell membrane. When ions move through [[ion transporter]]s (pumps) there is a gate in the pumps on both sides of the cell membrane and only one gate can be open at once. As a result, approximately 100 ions are forced through per second. [[Ion channel]]s have only one gate, and there only one kind of ion can stream through, at 10 million to 100 million ions per second. Calcium is required to open the pores, although calcium may work in reverse by blocking at least one of the pores. Carbonyl groups inside the pore on the amino acids mimic the water hydration that takes place in water solution by the nature of the electrostatic charges on four carbonyl groups inside the pore.

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===Nutrition===

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====Dietary recommendations====

The U.S. [[National Academy of Medicine]] (NAM), on behalf of both the U.S. and Canada, sets [[Dietary Reference Intake]]s, including Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs), or [[Adequate Intake]]s (AIs) for when there is not sufficient information to set EARs and RDAs.

For both males and females under 9 years of age, the AIs for potassium are: 400{{nbsp}}mg of potassium for 0 to 6-month-old infants, 860{{nbsp}}mg of potassium for 7 to 12-month-old infants, 2,000{{nbsp}}mg of potassium for 1 to 3-year-old children, and 2,300{{nbsp}}mg of potassium for 4 to 8-year-old children.

For males 9 years of age and older, the AIs for potassium are: 2,500{{nbsp}}mg of potassium for 9 to 13-year-old males, 3,000{{nbsp}}mg of potassium for 14 to 18-year-old males, and 3,400{{nbsp}}mg for males that are 19 years of age and older.

For females 9 years of age and older, the AIs for potassium are: 2,300{{nbsp}}mg of potassium for 9 to 18-year-old females, and 2,600{{nbsp}}mg of potassium for females that are 19 years of age and older.

For pregnant and lactating females, the AIs for potassium are: 2,600{{nbsp}}mg of potassium for 14 to 18-year-old pregnant females, 2,900{{nbsp}}mg for pregnant females that are 19 years of age and older; furthermore, 2,500{{nbsp}}mg of potassium for 14 to 18-year-old lactating females, and 2,800{{nbsp}}mg for lactating females that are 19 years of age and older. As for safety, the NAM also sets [[tolerable upper intake level]]s (ULs) for vitamins and minerals, but for potassium the evidence was insufficient, so no UL was established.

As of 2004, most Americans adults consume less than 3,000{{nbsp}}mg.

Likewise, in the European Union, in particular in Germany, and Italy, insufficient potassium intake is somewhat common. The [[National Health Service|British National Health Service]] recommends a similar intake, saying that adults need 3,500{{nbsp}}mg per day and that excess amounts may cause health problems such as stomach pain and [[diarrhea]].

In 2019, the [[National Academies of Sciences, Engineering, and Medicine]] revised the Adequate Intake for potassium to 2,600&nbsp;mg/day for females 19 years of age and older who are not pregnant or lactating, and 3,400&nbsp;mg/day for males 19 years of age and older.