Zinc: Difference between revisions

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===Physical properties===

Zinc is a bluish-white, lustrous, [[diamagnetic]] metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than [[iron]] and has a hexagonal [[crystal structure]], with a distorted form of [[Close-packing of equal spheres|hexagonal close packing]], in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair [[electrical conductivity|conductor of electricity]].~~<ref name="CRCp4-41" />~~ For a metal, zinc has relatively low melting (419.5 °C) and boiling point (907 °C). The melting point is the lowest of all the [[d-block]] metals aside from [[mercury (element)|mercury]] and [[cadmium]]; for this reason among others, zinc, cadmium, and mercury are often not considered to be [[transition metal]]s like the rest of the d-block metals.

Zinc is a bluish-white, lustrous, [[diamagnetic]] metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than [[iron]] and has a hexagonal [[crystal structure]], with a distorted form of [[Close-packing of equal spheres|hexagonal close packing]], in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair [[electrical conductivity|conductor of electricity]]. For a metal, zinc has relatively low melting (419.5 °C) and boiling point (907 °C). The melting point is the lowest of all the [[d-block]] metals aside from [[mercury (element)|mercury]] and [[cadmium]]; for this reason among others, zinc, cadmium, and mercury are often not considered to be [[transition metal]]s like the rest of the d-block metals.

Many [[alloy]]s contain zinc, including brass. Other metals long known to form binary alloys with zinc are [[aluminium]], [[antimony]], [[bismuth]], [[gold]], iron, [[lead]], mercury, [[silver]], [[tin]], [[magnesium]], [[cobalt]], [[nickel]], [[tellurium]], and [[sodium]]. Although neither zinc nor [[zirconium]] is [[Ferromagnetism|ferromagnetic]], their alloy, {{chem|ZrZn|2}}, exhibits ferromagnetism below 35 [[Kelvin|K]].

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Zinc has an [[electron configuration]] of [Ar]3d104s2 and is a member of the [[group 12 element|group 12]] of the [[periodic table]]. It is a moderately reactive [[metal]] and strong [[reducing agent]]. The surface of the pure metal [[tarnish]]es quickly, eventually forming a protective [[Passivation (chemistry)|passivating]] layer of the basic [[Hydrozincite|zinc carbonate]], {{chem|Zn|5|(OH)|6|(CO3)|2}}, by reaction with atmospheric [[carbon dioxide]].

Zinc burns in air with a bright bluish-green flame, giving off fumes of [[zinc oxide]].~~<ref name="Holl" />~~ Zinc reacts readily with [[acid]]s, [[alkali]]s and other non-metals. Extremely pure zinc reacts only slowly at [[room temperature]] with acids.~~<ref name="Holl" />~~ Strong acids, such as [[hydrochloric acid|hydrochloric]] or [[sulfuric acid]], can remove the passivating layer and the subsequent reaction with the acid releases hydrogen gas.

Zinc burns in air with a bright bluish-green flame, giving off fumes of [[zinc oxide]]. Zinc reacts readily with [[acid]]s, [[alkali]]s and other non-metals. Extremely pure zinc reacts only slowly at [[room temperature]] with acids. Strong acids, such as [[hydrochloric acid|hydrochloric]] or [[sulfuric acid]], can remove the passivating layer and the subsequent reaction with the acid releases hydrogen gas.

The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer [[electron shell|shell]] ''s'' electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d10. In aqueous solution an octahedral complex, {{chem|[Zn(H|2|O)6]|2+}} is the predominant species. The [[Volatility (chemistry)|volatilization]] of zinc in combination with zinc chloride at temperatures above 285 °C indicates the formation of {{chem|Zn|2|Cl|2}}, a zinc compound with a +1 oxidation state.~~<ref name="Holl" />~~ No compounds of zinc in positive oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist. Zn(III) is predicted to exist in the presence of strongly electronegative trianions; however, there exists some doubt around this possibility. But in 2021 another compound was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB11(CN)12.

The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer [[electron shell|shell]] ''s'' electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d10. In aqueous solution an octahedral complex, {{chem|[Zn(H|2|O)6]|2+}} is the predominant species. The [[Volatility (chemistry)|volatilization]] of zinc in combination with zinc chloride at temperatures above 285 °C indicates the formation of {{chem|Zn|2|Cl|2}}, a zinc compound with a +1 oxidation state. No compounds of zinc in positive oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist. Zn(III) is predicted to exist in the presence of strongly electronegative trianions; however, there exists some doubt around this possibility. But in 2021 another compound was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB11(CN)12.

Zinc chemistry is similar to the chemistry of the late first-row transition metals, [[nickel]] and copper, though it has a filled d-shell and compounds are [[diamagnetic]] and mostly colorless. The [[ionic radii]] of zinc and magnesium happen to be nearly identical. Because of this some of the equivalent salts have the same [[crystal structure]], and in other circumstances where ionic radius is a determining factor, the chemistry of zinc has much in common with that of magnesium. In other respects, there is little similarity with the late first-row transition metals. Zinc tends to form bonds with a greater degree of [[covalency]] and much more stable [[Complex (chemistry)|complexes]] with [[nitrogen|N]]- and [[sulfur|S]]- donors. Complexes of zinc are mostly 4- or 6- [[coordinate covalent bond|coordinate]], although 5-coordinate complexes are known.

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The sulfur dioxide is used for the production of sulfuric acid, which is necessary for the leaching process. If deposits of [[zinc carbonate]], [[zinc silicate]], or [[zinc-spinel]] (like the [[Skorpion Zinc|Skorpion Deposit]] in [[Namibia]]) are used for zinc production, the roasting can be omitted.

For further processing two basic methods are used: [[pyrometallurgy]] or [[electrowinning]]. Pyrometallurgy reduces zinc oxide with [[carbon]] or [[carbon monoxide]] at {{convert|950|C|F|abbr=on}} into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser.~~<ref name="Zinchand" />~~ The equations below describe this process:

For further processing two basic methods are used: [[pyrometallurgy]] or [[electrowinning]]. Pyrometallurgy reduces zinc oxide with [[carbon]] or [[carbon monoxide]] at {{convert|950|C|F|abbr=on}} into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser. The equations below describe this process:

: <chem>ZnO + C ->[950^\circ C] Zn + CO</chem>

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==Applications==

Major applications of zinc include, with percentages given for the US~~<ref name="USGS-yb2006" />~~

Major applications of zinc include, with percentages given for the US

# [[Galvanization|Galvanizing]] (55%)

# [[Brass]] and [[bronze]] (16%)

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Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a [[catalyst]] in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from [[ultraviolet radiation]] (UV). The [[semiconductor]] properties of zinc oxide make it useful in [[varistor]]s and photocopying products. The [[zinc zinc-oxide cycle]] is a two step [[Thermochemistry|thermochemical]] process based on zinc and zinc oxide for [[hydrogen production]].

[[Zinc chloride]] is often added to lumber as a [[fire retardant]] It is used in the manufacture of other chemicals. [[Zinc methyl]] ({{chem|Zn(CH3)|2}}) is used in a number of organic [[organic synthesis|syntheses]]. [[Zinc sulfide]] (ZnS) is used in [[luminescence|luminescent]] pigments such as on the hands of clocks, [[X-ray]] and television screens, and [[luminous paint]]s. Crystals of ZnS are used in [[laser]]s that operate in the mid-[[infrared]] part of the spectrum. [[Zinc sulfate]] is a chemical in [[dye]]s and pigments.~~<ref name="Heiserman1992p124" />~~ [[Zinc pyrithione]] is used in [[antifouling]] paints.

[[Zinc chloride]] is often added to lumber as a [[fire retardant]] It is used in the manufacture of other chemicals. [[Zinc methyl]] ({{chem|Zn(CH3)|2}}) is used in a number of organic [[organic synthesis|syntheses]]. [[Zinc sulfide]] (ZnS) is used in [[luminescence|luminescent]] pigments such as on the hands of clocks, [[X-ray]] and television screens, and [[luminous paint]]s. Crystals of ZnS are used in [[laser]]s that operate in the mid-[[infrared]] part of the spectrum. [[Zinc sulfate]] is a chemical in [[dye]]s and pigments. [[Zinc pyrithione]] is used in [[antifouling]] paints.

Zinc powder is sometimes used as a [[propellant]] in [[model rocket]]s. When a compressed mixture of 70% zinc and 30% [[sulfur]] powder is ignited there is a violent chemical reaction. This produces zinc sulfide, together with large amounts of hot gas, heat, and light.

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===Agriculture===

Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils. Zinc-deficient [[soil]] is [[Tillage|cultivated]] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas.~~<ref name="Broadley2007" />~~ Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide ([[zinc phosphide]]), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.

Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils. Zinc-deficient [[soil]] is [[Tillage|cultivated]] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas. Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide ([[zinc phosphide]]), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.

==Precautions==

@@ Line 15: / Line 15: @@
 ===Physical properties===
-Zinc is a bluish-white, lustrous, [[diamagnetic]] metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than [[iron]] and has a hexagonal [[crystal structure]], with a distorted form of [[Close-packing of equal spheres|hexagonal close packing]], in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150&nbsp;°C. Above 210&nbsp;°C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair [[electrical conductivity|conductor of electricity]].<ref name="CRCp4-41" /> For a metal, zinc has relatively low melting (419.5&nbsp;°C) and boiling point (907&nbsp;°C). The melting point is the lowest of all the [[d-block]] metals aside from [[mercury (element)|mercury]] and [[cadmium]]; for this reason among others, zinc, cadmium, and mercury are often not considered to be [[transition metal]]s like the rest of the d-block metals.
+Zinc is a bluish-white, lustrous, [[diamagnetic]] metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than [[iron]] and has a hexagonal [[crystal structure]], with a distorted form of [[Close-packing of equal spheres|hexagonal close packing]], in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150&nbsp;°C. Above 210&nbsp;°C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair [[electrical conductivity|conductor of electricity]]. For a metal, zinc has relatively low melting (419.5&nbsp;°C) and boiling point (907&nbsp;°C). The melting point is the lowest of all the [[d-block]] metals aside from [[mercury (element)|mercury]] and [[cadmium]]; for this reason among others, zinc, cadmium, and mercury are often not considered to be [[transition metal]]s like the rest of the d-block metals.
 Many [[alloy]]s contain zinc, including brass. Other metals long known to form binary alloys with zinc are [[aluminium]], [[antimony]], [[bismuth]], [[gold]], iron, [[lead]], mercury, [[silver]], [[tin]], [[magnesium]], [[cobalt]], [[nickel]], [[tellurium]], and [[sodium]]. Although neither zinc nor [[zirconium]] is [[Ferromagnetism|ferromagnetic]], their alloy, {{chem|ZrZn|2}}, exhibits ferromagnetism below 35&nbsp;[[Kelvin|K]].
@@ Line 48: / Line 48: @@
 Zinc has an [[electron configuration]] of [Ar]3d<sup>10</sup>4s<sup>2</sup> and is a member of the [[group 12 element|group 12]] of the [[periodic table]]. It is a moderately reactive [[metal]] and strong [[reducing agent]]. The surface of the pure metal [[tarnish]]es quickly, eventually forming a protective [[Passivation (chemistry)|passivating]] layer of the basic [[Hydrozincite|zinc carbonate]], {{chem|Zn|5|(OH)|6|(CO<sub>3</sub>)|2}}, by reaction with atmospheric [[carbon dioxide]].
-Zinc burns in air with a bright bluish-green flame, giving off fumes of [[zinc oxide]].<ref name="Holl" /> Zinc reacts readily with [[acid]]s, [[alkali]]s and other non-metals. Extremely pure zinc reacts only slowly at [[room temperature]] with acids.<ref name="Holl" /> Strong acids, such as [[hydrochloric acid|hydrochloric]] or [[sulfuric acid]], can remove the passivating layer and the subsequent reaction with the acid releases hydrogen gas.
+Zinc burns in air with a bright bluish-green flame, giving off fumes of [[zinc oxide]]. Zinc reacts readily with [[acid]]s, [[alkali]]s and other non-metals. Extremely pure zinc reacts only slowly at [[room temperature]] with acids. Strong acids, such as [[hydrochloric acid|hydrochloric]] or [[sulfuric acid]], can remove the passivating layer and the subsequent reaction with the acid releases hydrogen gas.
-The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer [[electron shell|shell]] ''s'' electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d<sup>10</sup>. In aqueous solution an octahedral complex, {{chem|[Zn(H|2|O)<sub>6</sub>]|2+}} is the predominant species. The [[Volatility (chemistry)|volatilization]] of zinc in combination with zinc chloride at temperatures above 285&nbsp;°C indicates the formation of {{chem|Zn|2|Cl|2}}, a zinc compound with a +1 oxidation state.<ref name="Holl" /> No compounds of zinc in positive oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist. Zn(III) is predicted to exist in the presence of strongly electronegative trianions; however, there exists some doubt around this possibility. But in 2021 another compound was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB<sub>11</sub>(CN)<sub>12</sub>.
+The chemistry of zinc is dominated by the +2 oxidation state. When compounds in this oxidation state are formed, the outer [[electron shell|shell]] ''s'' electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d<sup>10</sup>. In aqueous solution an octahedral complex, {{chem|[Zn(H|2|O)<sub>6</sub>]|2+}} is the predominant species. The [[Volatility (chemistry)|volatilization]] of zinc in combination with zinc chloride at temperatures above 285&nbsp;°C indicates the formation of {{chem|Zn|2|Cl|2}}, a zinc compound with a +1 oxidation state. No compounds of zinc in positive oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist. Zn(III) is predicted to exist in the presence of strongly electronegative trianions; however, there exists some doubt around this possibility. But in 2021 another compound was reported with more evidence that had the oxidation state of +3 with the formula ZnBeB<sub>11</sub>(CN)<sub>12</sub>.
 Zinc chemistry is similar to the chemistry of the late first-row transition metals, [[nickel]] and copper, though it has a filled d-shell and compounds are [[diamagnetic]] and mostly colorless. The [[ionic radii]] of zinc and magnesium happen to be nearly identical. Because of this some of the equivalent salts have the same [[crystal structure]], and in other circumstances where ionic radius is a determining factor, the chemistry of zinc has much in common with that of magnesium. In other respects, there is little similarity with the late first-row transition metals. Zinc tends to form bonds with a greater degree of [[covalency]] and much more stable [[Complex (chemistry)|complexes]] with [[nitrogen|N]]- and [[sulfur|S]]- donors. Complexes of zinc are mostly 4- or 6- [[coordinate covalent bond|coordinate]], although 5-coordinate complexes are known.
@@ Line 166: / Line 166: @@
 The sulfur dioxide is used for the production of sulfuric acid, which is necessary for the leaching process. If deposits of [[zinc carbonate]], [[zinc silicate]], or [[zinc-spinel]] (like the [[Skorpion Zinc|Skorpion Deposit]] in [[Namibia]]) are used for zinc production, the roasting can be omitted.
-For further processing two basic methods are used: [[pyrometallurgy]] or [[electrowinning]]. Pyrometallurgy reduces zinc oxide with [[carbon]] or [[carbon monoxide]] at {{convert|950|C|F|abbr=on}} into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser.<ref name="Zinchand" /> The equations below describe this process:
+For further processing two basic methods are used: [[pyrometallurgy]] or [[electrowinning]]. Pyrometallurgy reduces zinc oxide with [[carbon]] or [[carbon monoxide]] at {{convert|950|C|F|abbr=on}} into the metal, which is distilled as zinc vapor to separate it from other metals, which are not volatile at those temperatures. The zinc vapor is collected in a condenser. The equations below describe this process:
 : <chem>ZnO + C ->[950^\circ C] Zn + CO</chem>
@@ Line 193: / Line 193: @@
 ==Applications==
-Major applications of zinc include, with percentages given for the US<ref name="USGS-yb2006" />
+Major applications of zinc include, with percentages given for the US
 # [[Galvanization|Galvanizing]] (55%)
 # [[Brass]] and [[bronze]] (16%)
@@ Line 228: / Line 228: @@
 Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a [[catalyst]] in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from [[ultraviolet radiation]] (UV). The [[semiconductor]] properties of zinc oxide make it useful in [[varistor]]s and photocopying products. The [[zinc zinc-oxide cycle]] is a two step [[Thermochemistry|thermochemical]] process based on zinc and zinc oxide for [[hydrogen production]].
-[[Zinc chloride]] is often added to lumber as a [[fire retardant]] It is used in the manufacture of other chemicals. [[Zinc methyl]] ({{chem|Zn(CH<sub>3</sub>)|2}}) is used in a number of organic [[organic synthesis|syntheses]]. [[Zinc sulfide]] (ZnS) is used in [[luminescence|luminescent]] pigments such as on the hands of clocks, [[X-ray]] and television screens, and [[luminous paint]]s. Crystals of ZnS are used in [[laser]]s that operate in the mid-[[infrared]] part of the spectrum. [[Zinc sulfate]] is a chemical in [[dye]]s and pigments.<ref name="Heiserman1992p124" /> [[Zinc pyrithione]] is used in [[antifouling]] paints.
+[[Zinc chloride]] is often added to lumber as a [[fire retardant]] It is used in the manufacture of other chemicals. [[Zinc methyl]] ({{chem|Zn(CH<sub>3</sub>)|2}}) is used in a number of organic [[organic synthesis|syntheses]]. [[Zinc sulfide]] (ZnS) is used in [[luminescence|luminescent]] pigments such as on the hands of clocks, [[X-ray]] and television screens, and [[luminous paint]]s. Crystals of ZnS are used in [[laser]]s that operate in the mid-[[infrared]] part of the spectrum. [[Zinc sulfate]] is a chemical in [[dye]]s and pigments. [[Zinc pyrithione]] is used in [[antifouling]] paints.
 Zinc powder is sometimes used as a [[propellant]] in [[model rocket]]s. When a compressed mixture of 70% zinc and 30% [[sulfur]] powder is ignited there is a violent chemical reaction. This produces zinc sulfide, together with large amounts of hot gas, heat, and light.
@@ Line 351: / Line 351: @@
 ===Agriculture===
-Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils. Zinc-deficient [[soil]] is [[Tillage|cultivated]] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas.<ref name="Broadley2007" /> Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide ([[zinc phosphide]]), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.
+Zinc deficiency appears to be the most common micronutrient deficiency in crop plants; it is particularly common in high-pH soils. Zinc-deficient [[soil]] is [[Tillage|cultivated]] in the cropland of about half of Turkey and India, a third of China, and most of Western Australia. Substantial responses to zinc fertilization have been reported in these areas. Plants that grow in soils that are zinc-deficient are more susceptible to disease. Zinc is added to the soil primarily through the weathering of rocks, but humans have added zinc through fossil fuel combustion, mine waste, phosphate fertilizers, pesticide ([[zinc phosphide]]), limestone, manure, sewage sludge, and particles from galvanized surfaces. Excess zinc is toxic to plants, although zinc toxicity is far less widespread.
 ==Precautions==