Palladium
Palladium General
| Name:Palladium | Symbol:Pd |
| Type:Transition Metal | Atomic weight:106.4 |
| Density @ 293 K:12.02 g/cm3 | Atomic volume:8.9 cm3/mol |
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Discovered:
Palladium was discovered by William.H. Wollaston in 1803 in platinum ore. He isolated palladium metal in a series of chemical reactions, finally heating palladium cyanide to extract palladium metal. The element is named after the Greek goddess of wisdom "Pallas'. |
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Palladium States
| State (s, l, g):solid | |
| Melting point: 1828 K (1555 °C) | Boiling point:3233 K (2960 °C) |
Palladium Energies
| Specific heat capacity: 0.24 J g-1 K-1 | Heat of atomization:378 kJ mol-1 |
| Heat of fusion:17.60 kJ mol-1 | Heat of vaporization :357.0 kJ mol-1 |
| 1st ionization energy:804.7 kJ mol-1 | 2nd ionization energy:1894 kJ mol-1 |
| 3rd ionization energy:3177.2 kJ mol-1 | Electron affinity: 53.7 kJ mol-1 |
Palladium Oxidation & Electrons
| Shells:2,8,18,18 | Electron configuration:[Kr] 4d10 |
| Minimum oxidation number:0 | Maximum oxidation number:4 |
| Min. common oxidation no.:0 | Max. common oxidation no.:4 |
| Electronegativity (Pauling Scale):2.2 | Polarizability volume:4.8 Å3 |
Palladium Appearance & Characteristics
| Structure:ccp (cubic close-packed) | Color:silvery-white |
| Hardness: 4.8 mohs | |
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Harmful effects:
Palladium is considered to be of low toxicity. |
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Characteristics:
Palladium is a rare, lustrous, silvery-white metal. It is malleable and ductile and, like gold, palladium can be beaten into thin leaf. It does not tarnish in air but does tarnish lightly in moist air containing sulfur. The metal is strongly resistant to corrosion in air and to the action of acids (except nitric acid) at ordinary temperatures. Palladium is remarkable in its capacity to absorb up to 900 times its own volume of hydrogen. As it absorbs the hydrogen, it expands visibly, like a sponge swelling up when absorbing water. Uses: The largest use of palladium is in catalytic converters for automobiles. Finely divided palladium is used as a catalyst for hydrogenation/dehydrogenation reactions and for petroleum cracking. The metal is used in jewelry, for example in white gold (an alloy of gold decolorized by the addition of palladium). Palladium is used in dentistry, watch making, and in making surgical instruments and electrical contacts. It is also used to purify hydrogen because the gas easily diffuses through heated palladium. |
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Palladium Reactions
| Reaction with air:mild w/ht, ⇒ PdO | Reaction with 6 M HCl:none |
| Reaction with 15 M HNO3:mild ⇒ Pd(NO3)2 | Reaction with 6 M NaOH:none |
Palladium Compounds
| Oxide(s):PdO, PdO2 | Chloride(s): PdCl2 |
| Hydride(s):PdH2 |
Palladium Radius
| Atomic radius:137 pm | Ionic radius (1+ ion):73 pm |
| Ionic radius (2+ ion):100 pm | Ionic radius (3+ ion):90 pm |
| Ionic radius (2- ion):pm | Ionic radius (1- ion):pm |
Palladium Conductivity
| Thermal conductivity:71.8 W m-1 K-1 | Electrical conductivity:10 x 106 S m-1 |
Palladium Abundance & Isotopes
| Abundance earth's crust:15 parts per billion by weight, 2 parts per billion by moles | |
| Abundance solar system:3 parts per billion by weight, 40 part per trillion by moles | |
| Cost, pure:$5833 per 100g | |
| Cost, bulk:$1571 per 100g | |
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Source:
Palladium occurs in nature as a free metal and also alloyed with gold, platinum, and other platinum group metals. Commercially, it is produced from nickel-copper ore deposits where it is found in small quantities. |
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Isotopes:
Palladium has 33 isotopes whose half-lives are known, with mass numbers from 94 to 120. Of these, six are stable: 102Pd, 104Pd, 105Pd, 106Pd, 108Pd, and 110Pd. |
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Palladium Other
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Other:
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