Difference between revisions of "Zinc"

From Sciencemadness Wiki
Jump to: navigation, search
(Created page with "A broken bar of pure zinc. (From zts16's collection)'''Zinc''' is a transition metal with symbol Zn and atomic number 30...")
 
 
(8 intermediate revisions by 2 users not shown)
Line 1: Line 1:
−
[[File:Zinc_bar.jpg|thumb|300px|A broken bar of pure zinc.
+
{{Infobox element
−
(From zts16's collection)]]'''Zinc''' is a [[Transition metal|transition metal]] with symbol Zn and atomic number 30. It is a useful [[Reducing agent|reducing agent]] which is readily available. It exists in the oxidation state +2 in solution and may be readily plated out of solution, despite its reducing tendencies. Its compounds are colorless due to the zinc ion's [Ar] 3d<sup>10</sup> electron configuration, with a filled d-shell.
+
<!-- top -->
 +
|image name=Zinc bar Zts16.jpg
 +
|image alt=
 +
|image size=250
 +
|image name comment=A broken bar of pure zinc.(From zts16's collection)
 +
|image name 2=
 +
|image alt 2=
 +
|image size 2=
 +
|image name 2 comment=
 +
<!-- General properties -->
 +
|name=Zinc
 +
|symbol=Zn
 +
|pronounce=
 +
|pronounce ref=
 +
|pronounce comment=
 +
|pronounce 2=
 +
|alt name=
 +
|alt names=
 +
|allotropes=
 +
|appearance=Silvery-bluish metal
 +
<!-- Periodic table -->
 +
|above=-
 +
|below=[[Cadmium|Cd]]
 +
|left=[[Copper]]
 +
|right=[[Gallium]]
 +
|number=30
 +
|atomic mass=65.38(2)
 +
|atomic mass 2=
 +
|atomic mass ref=
 +
|atomic mass comment=
 +
|series=
 +
|series ref=
 +
|series comment=Transition metals<br>Post-transition metals (debated)
 +
|series color=
 +
|group=
 +
|group ref=
 +
|group comment=XII
 +
|period=4
 +
|period ref=
 +
|period comment=
 +
|block=d
 +
|block ref=
 +
|block comment=
 +
|electron configuration=[Ar] 3d<sup>10</sup> 4s<sup>2</sup>
 +
|electron configuration ref=
 +
|electron configuration comment=
 +
|electrons per shell= 2, 8, 18, 2
 +
|electrons per shell ref=
 +
|electrons per shell comment=
 +
<!-- Physical properties -->
 +
|physical properties comment=
 +
|color=Silvery-gray, bluish
 +
|phase=Solid
 +
|phase ref=
 +
|phase comment=
 +
|melting point K=692.68
 +
|melting point C=419.53
 +
|melting point F=787.15
 +
|melting point ref=
 +
|melting point comment=
 +
|boiling point K=1180
 +
|boiling point C=907
 +
|boiling point F=​1665
 +
|boiling point ref=
 +
|boiling point comment=
 +
|sublimation point K=
 +
|sublimation point C=
 +
|sublimation point F=
 +
|sublimation point ref=
 +
|sublimation point comment=
 +
|density gplstp=
 +
|density gplstp ref=
 +
|density gplstp comment=
 +
|density gpcm3nrt=7.14
 +
|density gpcm3nrt ref=
 +
|density gpcm3nrt comment=
 +
|density gpcm3nrt 2=
 +
|density gpcm3nrt 2 ref=
 +
|density gpcm3nrt 2 comment=
 +
|density gpcm3nrt 3=
 +
|density gpcm3nrt 3 ref=
 +
|density gpcm3nrt 3 comment=
 +
|density gpcm3mp=6.57
 +
|density gpcm3mp ref=
 +
|density gpcm3mp comment=
 +
|density gpcm3bp=
 +
|density gpcm3bp ref=
 +
|density gpcm3bp comment=
 +
|molar volume=
 +
|molar volume unit =
 +
|molar volume ref=
 +
|molar volume comment=
 +
|triple point K=
 +
|triple point kPa=
 +
|triple point ref=
 +
|triple point comment=
 +
|triple point K 2=
 +
|triple point kPa 2=
 +
|triple point 2 ref=
 +
|triple point 2 comment=
 +
|critical point K=
 +
|critical point MPa=
 +
|critical point ref=
 +
|critical point comment=
 +
|heat fusion=7.32
 +
|heat fusion ref=
 +
|heat fusion comment=
 +
|heat fusion 2=
 +
|heat fusion 2 ref=
 +
|heat fusion 2 comment=
 +
|heat vaporization=115
 +
|heat vaporization ref=
 +
|heat vaporization comment=
 +
|heat capacity=25.470
 +
|heat capacity ref=
 +
|heat capacity comment=
 +
|heat capacity 2=
 +
|heat capacity 2 ref=
 +
|heat capacity 2 comment=
 +
|vapor pressure 1=610
 +
|vapor pressure 10=670
 +
|vapor pressure 100=750
 +
|vapor pressure 1 k=852
 +
|vapor pressure 10 k=990
 +
|vapor pressure 100 k=1179
 +
|vapor pressure ref=
 +
|vapor pressure comment=
 +
|vapor pressure 1 2=
 +
|vapor pressure 10 2=
 +
|vapor pressure 100 2=
 +
|vapor pressure 1 k 2=
 +
|vapor pressure 10 k 2=
 +
|vapor pressure 100 k 2=
 +
|vapor pressure 2 ref=
 +
|vapor pressure 2 comment=
 +
<!-- Atomic properties -->
 +
|atomic properties comment=
 +
|oxidation states= -2, 0, +1, '''+2'''
 +
|oxidation states ref=
 +
|oxidation states comment=(an amphoteric oxide)
 +
|electronegativity=1.65
 +
|electronegativity ref=
 +
|electronegativity comment=
 +
|ionization energy 1=906.4
 +
|ionization energy 1 ref=
 +
|ionization energy 1 comment=
 +
|ionization energy 2=1733.3
 +
|ionization energy 2 ref=
 +
|ionization energy 2 comment=
 +
|ionization energy 3=3833
 +
|ionization energy 3 ref=
 +
|ionization energy 3 comment=
 +
|number of ionization energies=10
 +
|ionization energy ref=
 +
|ionization energy comment=
 +
|atomic radius=134
 +
|atomic radius ref=
 +
|atomic radius comment=
 +
|atomic radius calculated=
 +
|atomic radius calculated ref=
 +
|atomic radius calculated comment=
 +
|covalent radius=122±4
 +
|covalent radius ref=
 +
|covalent radius comment=
 +
|Van der Waals radius=139
 +
|Van der Waals radius ref=
 +
|Van der Waals radius comment=
 +
<!-- Miscellanea -->
 +
|crystal structure=
 +
|crystal structure prefix=
 +
|crystal structure ref=
 +
|crystal structure comment=​hexagonal close-packed (hcp)
 +
|crystal structure 2=
 +
|crystal structure 2 prefix=
 +
|crystal structure 2 ref=
 +
|crystal structure 2 comment=
 +
|speed of sound=
 +
|speed of sound ref=
 +
|speed of sound comment=
 +
|speed of sound rod at 20=
 +
|speed of sound rod at 20 ref=
 +
|speed of sound rod at 20 comment=
 +
|speed of sound rod at r.t.=3850
 +
|speed of sound rod at r.t. ref=
 +
|speed of sound rod at r.t. comment= (rolled)
 +
|thermal expansion=
 +
|thermal expansion ref=
 +
|thermal expansion comment=
 +
|thermal expansion at 25=30.2
 +
|thermal expansion at 25 ref=
 +
|thermal expansion at 25 comment=
 +
|thermal conductivity=116
 +
|thermal conductivity ref=
 +
|thermal conductivity comment=
 +
|thermal conductivity 2=
 +
|thermal conductivity 2 ref=
 +
|thermal conductivity 2 comment=
 +
|thermal diffusivity=
 +
|thermal diffusivity ref=
 +
|thermal diffusivity comment=
 +
|electrical resistivity=
 +
|electrical resistivity unit prefix=
 +
|electrical resistivity ref=
 +
|electrical resistivity comment=
 +
|electrical resistivity at 0=
 +
|electrical resistivity at 0 ref=
 +
|electrical resistivity at 0 comment=
 +
|electrical resistivity at 20=59.0
 +
|electrical resistivity at 20 ref=
 +
|electrical resistivity at 20 comment=
 +
|band gap=
 +
|band gap ref=
 +
|band gap comment=
 +
|Curie point K=
 +
|Curie point ref=
 +
|Curie point comment=
 +
|magnetic ordering=Diamagnetic
 +
|magnetic ordering ref=
 +
|magnetic ordering comment=
 +
|tensile strength=
 +
|tensile strength ref=
 +
|tensile strength comment=
 +
|Young's modulus=108
 +
|Young's modulus ref=
 +
|Young's modulus comment=
 +
|Shear modulus=43
 +
|Shear modulus ref=
 +
|Shear modulus comment=
 +
|Bulk modulus=70
 +
|Bulk modulus ref=
 +
|Bulk modulus comment=
 +
|Poisson ratio=0.25
 +
|Poisson ratio ref=
 +
|Poisson ratio comment=
 +
|Mohs hardness=2.5
 +
|Mohs hardness ref=
 +
|Mohs hardness comment=
 +
|Mohs hardness 2=
 +
|Mohs hardness 2 ref=
 +
|Mohs hardness 2 comment=
 +
|Vickers hardness=
 +
|Vickers hardness ref=
 +
|Vickers hardness comment=
 +
|Brinell hardness=327–412
 +
|Brinell hardness ref=
 +
|Brinell hardness comment=
 +
|CAS number=7440-66-6
 +
|CAS number ref=
 +
|CAS number comment=
 +
<!-- History -->
 +
|naming=
 +
|predicted by=
 +
|prediction date ref=
 +
|prediction date=
 +
|discovered by= Indian metallurgists
 +
|discovery date ref=
 +
|discovery date=<1000 B.C.
 +
|first isolation by=Andreas Sigismund Marggraf
 +
|first isolation date ref=
 +
|first isolation date=1746
 +
|discovery and first isolation by=
 +
|named by=
 +
|named date ref=
 +
|named date=
 +
|history comment label=
 +
|history comment=
 +
<!-- Isotopes -->
 +
|isotopes=
 +
|isotopes comment=
 +
|engvar=
 +
}}
 +
'''Zinc''' is a [[transition metal]] with symbol '''Zn''' and atomic number 30. It is a useful [[Reducer|reducing agent]] which is readily available. It exists in the oxidation state +2 in solution and may be readily plated out of solution, despite its reducing tendencies. Its compounds are colorless due to the zinc ion's [Ar] 3d<sup>10</sup> electron configuration, with a filled d-shell.
 +
 
 
==Properties==
 
==Properties==
 
===Physical properties===
 
===Physical properties===
 
Zinc is a silvery metal with a bluish cast. Older pieces of zinc may appear to have a white coating of [[zinc oxide]] or [[zinc carbonate]] on the surface. It has a relatively low melting point of 420 °C.
 
Zinc is a silvery metal with a bluish cast. Older pieces of zinc may appear to have a white coating of [[zinc oxide]] or [[zinc carbonate]] on the surface. It has a relatively low melting point of 420 °C.
 +
 
===Chemical properties===
 
===Chemical properties===
 
Zinc metal is stable in both air and water, but it will react readily with dilute [[Acid|acids]]. However, extremely pure zinc metal exhibits reduced reactivity towards acids. Zinc is amphoteric and will dissolve in strong [[Base|bases]] to form [[Zincate|zincates]]. Zinc dust burns in air with a greenish-white flame to form zinc oxide.
 
Zinc metal is stable in both air and water, but it will react readily with dilute [[Acid|acids]]. However, extremely pure zinc metal exhibits reduced reactivity towards acids. Zinc is amphoteric and will dissolve in strong [[Base|bases]] to form [[Zincate|zincates]]. Zinc dust burns in air with a greenish-white flame to form zinc oxide.
  
 
The potential for the reaction Zn<sup>2+</sup> + 2e<sup>-</sup> → Zn is -0.76 V. Despite this, zinc metal can be plated out of solution without issues such as hydroxide formation.
 
The potential for the reaction Zn<sup>2+</sup> + 2e<sup>-</sup> → Zn is -0.76 V. Despite this, zinc metal can be plated out of solution without issues such as hydroxide formation.
−
==Availability and Preparation==
 
−
*United States pennies minted after 1982 are relatively pure zinc clad with copper. Because zinc melts at only 420 °C(787.2 °F), it can be melted and cast into the desired shape using a blowtorch or furnace. Though some copper impurities will likely remain, the large difference in the reactivity of the two metals means that most uses of zinc will be unaffected by this.
 
−
* Zinc metal can be found at boating shops as sacrificial anodes for rust protection. These pieces may contain small amounts of [[cadmium]] in them, so they should be handled with care.
 
  
−
*Zinc is used as a casing in some lantern batteries.
+
==Availability==
 +
United States pennies minted after 1982 are relatively pure zinc clad with copper. Because zinc melts at only 420 °C (787.2 °F), it can be melted and cast into the desired shape using a blowtorch or furnace. Though some copper impurities will likely remain, the large difference in the reactivity of the two metals means that most uses of zinc will be unaffected by this.
  
−
*Zinc, chemically, can most commonly be purchased as zinc sulfate.
+
Zinc metal can be found at boating shops as sacrificial anodes for rust protection. These pieces may contain small amounts of [[cadmium]] metal in them, so they should be handled with care.
 +
 
 +
Zinc can also be found in wheel weights (aka tire balance), where it may also contain impurities such as [[aluminium]], [[copper]], [[lead]], [[antimony]] or [[cadmium]]. Only the wheel weights labeled "Zn" contain zinc.
 +
 
 +
Zinc is commonly found in a variety of everyday items, in the form of [[zamak]], a zinc-aluminium alloy. Unless you desire pure zinc, this form of zinc is suitable for most applications. If you want to extract the zinc metal from the alloy, dissolve the metal in NaOH or sulfuric acid and electroplate the metal from the solution
 +
 
 +
Zinc is used as a casing in most zinc-carbon batteries.
 +
 
 +
Zinc, chemically, can most commonly be purchased as zinc sulfate.
 +
 
 +
==Isolation==
 +
Zinc metal can be made by reducing [[zinc oxide]] with carbon in a furnace.
 +
 
 +
Zinc can be prepared via electrowinning from a diluted zinc sulfate solution.
  
 
==Projects==
 
==Projects==
Line 22: Line 306:
 
*Reducing Cr(III) to Cr(II)
 
*Reducing Cr(III) to Cr(II)
 
*Making [[zinc sulfide]]
 
*Making [[zinc sulfide]]
−
*[http://www.sciencemadness.org/talk/viewthread.php?tid=30150 The synthesis of] anhydrous [[Aluminum chloride|aluminum chloride]] through thermite
+
*[http://www.sciencemadness.org/talk/viewthread.php?tid=30150 The synthesis of] anhydrous [[aluminium chloride]] through thermite
  
−
==Safety==
+
==Handling==
−
Zinc is not very toxic by itself. Zinc sacrificial anodes, however, may contain the dangerous metal cadmium, which is notoriously difficult to remove. Zinc dust is flammable, and class-D fire extinguishers should be used to deal with these types of fires. Water may aggravate a zinc fire and should not be used.
+
===Safety===
 +
Zinc is not very toxic by itself. Zinc sacrificial anodes, however, may contain the dangerous metal [[cadmium]], which is notoriously difficult to remove. Zinc dust is flammable, and class-D fire extinguishers should be used to deal with these types of fires. Water may aggravate a zinc fire and should not be used.
  
 
'''Never consume zinc or its compounds, when produced in the laboratory, as a supplement.'''
 
'''Never consume zinc or its compounds, when produced in the laboratory, as a supplement.'''
  
 
Older grades of zinc, and those used in zinc-carbon batteries, may contain arsenic and lead. Upon melting, these emit arsenic compounds into the air as fumes, and are extremely hazardous. Take caution when melting an unknown-purity sample of zinc. Even the purest grades of zinc contain small but significant amounts of cadmium.
 
Older grades of zinc, and those used in zinc-carbon batteries, may contain arsenic and lead. Upon melting, these emit arsenic compounds into the air as fumes, and are extremely hazardous. Take caution when melting an unknown-purity sample of zinc. Even the purest grades of zinc contain small but significant amounts of cadmium.
 +
 +
===Storage===
 +
Bulk zinc metal can be stored in any type of container. It slowly develops an oxide layer which further protects from corrosion. Zinc powder should be stored in small bottles, away from open air.
 +
 +
===Disposal===
 +
Zinc and its compounds have little toxicity and no special disposal is required. Technical grade zinc however, may contain traces of heavy metals, and the zinc waste should be taken to disposal facilities.
 +
 +
==See also==
 +
*[[Zamak]]
 +
 +
==References==
 +
<references/>
 +
===Relevant Sciencemadness threads===
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=63424 anyway to recover and purify the zinc from old batteries?]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=20949 Storing Zinc metal powder - Safety]
 +
 +
[[Category:Elements]]
 +
[[Category:Metals]]
 +
[[Category:Transition metals]]
 +
[[Category:Post-transition metals]]
 +
[[Category:Reducing agents]]
 +
[[Category:Essential reagents]]
 +
[[Category:Readily available chemicals]]
 +
[[Category:Materials isolable by electrowinning]]
 +
[[Category:Materials unstable in acidic solution]]
 +
[[Category:D-block]]
 +
[[Category:Volatile metals]]

Latest revision as of 17:21, 13 February 2021

Zinc,  30Zn
Zinc bar Zts16.jpg
A broken bar of pure zinc.(From zts16's collection)
General properties
Name, symbol Zinc, Zn
Appearance Silvery-bluish metal
Zinc in the periodic table
-
↑
Zn
↓
Cd
Copper ← Zinc → Gallium
Atomic number 30
Standard atomic weight (Ar) 65.38(2)
Element category Transition metals
Post-transition metals (debated)
Group, block XII; d-block
Period period 4
Electron configuration [Ar] 3d10 4s2
per shell
 2, 8, 18, 2
Physical properties
Silvery-gray, bluish
Phase Solid
Melting point 692.68 K ​(419.53 °C, ​787.15 °F)
Boiling point 1180 K ​(907 °C, ​​1665 °F)
Density near r.t. 7.14 g/cm3
when liquid, at  6.57 g/cm3
Heat of fusion 7.32 kJ/mol
Heat of 115 kJ/mol
Molar heat capacity 25.470 J/(mol·K)
 pressure
Atomic properties
Oxidation states -2, 0, +1, +2 ​(an amphoteric oxide)
Electronegativity Pauling scale: 1.65
energies 1st: 906.4 kJ/mol
2nd: 1733.3 kJ/mol
3rd: 3833 kJ/mol
(more)
Atomic radius empirical: 134 pm
Covalent radius 122±4 pm
Van der Waals radius 139 pm
Miscellanea
Crystal structure ​​hexagonal close-packed (hcp)
Speed of sound thin rod 3850 m/s (at ) (rolled)
Thermal expansion 30.2 µm/(m·K) (at 25 °C)
Thermal conductivity 116 W/(m·K)
Electrical resistivity 59.0 Ω·m (at 20 °C)
Magnetic ordering Diamagnetic
Young's modulus 108 GPa
Shear modulus 43 GPa
Bulk modulus 70 GPa
Poisson ratio 0.25
Mohs hardness 2.5
Brinell hardness 327–412 MPa
CAS Registry Number 7440-66-6
History
Discovery Indian metallurgists (<1000 B.C.)
First isolation Andreas Sigismund Marggraf (1746)
· references

Zinc is a transition metal with symbol Zn and atomic number 30. It is a useful reducing agent which is readily available. It exists in the oxidation state +2 in solution and may be readily plated out of solution, despite its reducing tendencies. Its compounds are colorless due to the zinc ion's [Ar] 3d10 electron configuration, with a filled d-shell.

Properties

Physical properties

Zinc is a silvery metal with a bluish cast. Older pieces of zinc may appear to have a white coating of zinc oxide or zinc carbonate on the surface. It has a relatively low melting point of 420 °C.

Chemical properties

Zinc metal is stable in both air and water, but it will react readily with dilute acids. However, extremely pure zinc metal exhibits reduced reactivity towards acids. Zinc is amphoteric and will dissolve in strong bases to form zincates. Zinc dust burns in air with a greenish-white flame to form zinc oxide.

The potential for the reaction Zn2+ + 2e- → Zn is -0.76 V. Despite this, zinc metal can be plated out of solution without issues such as hydroxide formation.

Availability

United States pennies minted after 1982 are relatively pure zinc clad with copper. Because zinc melts at only 420 °C (787.2 °F), it can be melted and cast into the desired shape using a blowtorch or furnace. Though some copper impurities will likely remain, the large difference in the reactivity of the two metals means that most uses of zinc will be unaffected by this.

Zinc metal can be found at boating shops as sacrificial anodes for rust protection. These pieces may contain small amounts of cadmium metal in them, so they should be handled with care.

Zinc can also be found in wheel weights (aka tire balance), where it may also contain impurities such as aluminium, copper, lead, antimony or cadmium. Only the wheel weights labeled "Zn" contain zinc.

Zinc is commonly found in a variety of everyday items, in the form of zamak, a zinc-aluminium alloy. Unless you desire pure zinc, this form of zinc is suitable for most applications. If you want to extract the zinc metal from the alloy, dissolve the metal in NaOH or sulfuric acid and electroplate the metal from the solution

Zinc is used as a casing in most zinc-carbon batteries.

Zinc, chemically, can most commonly be purchased as zinc sulfate.

Isolation

Zinc metal can be made by reducing zinc oxide with carbon in a furnace.

Zinc can be prepared via electrowinning from a diluted zinc sulfate solution.

Projects

Handling

Safety

Zinc is not very toxic by itself. Zinc sacrificial anodes, however, may contain the dangerous metal cadmium, which is notoriously difficult to remove. Zinc dust is flammable, and class-D fire extinguishers should be used to deal with these types of fires. Water may aggravate a zinc fire and should not be used.

Never consume zinc or its compounds, when produced in the laboratory, as a supplement.

Older grades of zinc, and those used in zinc-carbon batteries, may contain arsenic and lead. Upon melting, these emit arsenic compounds into the air as fumes, and are extremely hazardous. Take caution when melting an unknown-purity sample of zinc. Even the purest grades of zinc contain small but significant amounts of cadmium.

Storage

Bulk zinc metal can be stored in any type of container. It slowly develops an oxide layer which further protects from corrosion. Zinc powder should be stored in small bottles, away from open air.

Disposal

Zinc and its compounds have little toxicity and no special disposal is required. Technical grade zinc however, may contain traces of heavy metals, and the zinc waste should be taken to disposal facilities.

See also

References

Relevant Sciencemadness threads

Retrieved from "https://www.sciencemadness.org/smwiki/index.php?title=Zinc&oldid=13828"