Discuss the unique properties of the first-row transition metals in the context of their oxidation state.
Discuss why Cu, Ag, and Au are coinage metals.
The group 12 metals form some important compounds.
Discuss why lanthanides are difficult to separate from each other.
The formula and structure of the yttrium, barium, copper, Michael Dalton, Photographs and oxygen high-temperature Whiskers of rutile, TiO2, in quartz and titanium are described.
Titanium metal, obtained from rutile, is used in industry because of its high strength and low density.
TiO2 is used in paints and specialty papers.
Some of the transition elements are rare and limited use, but others are crucial to modern life.
Iron and important alloying metals are important in the manufacture of steel and are among the transition elements.
Transition metals are the best conductors.
The compounds of transition metals are the main components of paint pigments.
The essential material for photographic film is silver.
The compounds of the f-block elements are used in materials for color television screens.
The transition metals are essential elements for living organisms.
Both theoretical and practical significance can be found in the -block and f-block elements.
Understanding fundamental aspects of bonding, magnetism, and reaction chemistry is provided by these elements and their compounds.
The ready availability of electrons and orbitals for metallic bonding results in the high melting points, good electrical conductivity, and moderate-to-extreme hardness of the transition elements.
The transition elements have some similarities, but they also have some unique properties that make them useful in different ways.
There is little variation in the atomic radii across the first transition series.
This does not cause much of a change in atomic radius, especially in the middle of the series.
Important differences appear when elements of the first transition series are compared with elements of the second and third series.
The atomic radius of W is the same as that of Mo, but not larger.
Between Mo and W, 32 electrons must be added, and 14 of them enter the 4f subshell.
In screening outer-shell electrons from the nucleus, f subshell electrons are not very effective.
M1s2 is the only one where the ion is Sc3
Increasing the atomic number would be expected.
Atomic radii don't change.
The 4f subshell is filled in a number of elements.
Some of the main-group elements in Chapters 21 and 22 may have multiple oxidation states.
One particular oxidation state is the most common for an element.
Ti atoms use all four electrons beyond the argon core in compound formation and show the oxidation state +4.
Ti atoms can use fewer electrons if they lose the 4s2 electrons to form the ion Ti2+.
Fe, Co, and Ni all have one oxidation state, but they don't show the wide variety found in the earlier members of the first transition series.
They do not show a maximum oxidation state.
The transition elements differ in the ease with which oxidation states can be attained and in their stabilities.
In transition metal complexes oxidation state is occasionally found.
Co3+1aq2 oxidizes water to O21g2 and is reduced to Co2+1aq2.
In certain complex ion, Co3 can be stable.
When oxide or fluoride is bound to the metal, higher oxidation states are stable.
The reverse of the trend seen for main-group elements is seen when the sta bility of higher oxidation states increases in descending a group of the periodic table.
Group 6 has oxidation states ranging from +6 to -2.
The number of compounds in the +6 oxidation state is limited.
Mo and W have a rich chemistry in the oxidation states of +4 and +5.
The oxidation state of chromium is stable.
Mo and W are not obtainable as the simple +2 cation because it is a strong reducing agent.
In other groups of transition metals, this trend favors lower oxidation states for the first group member and higher oxidation states for the later members.
Os forms the stable oxide OsO4 with Os in the +8 oxidation state, even though Fe does not exhibit an oxidation state corresponding to the group number.
The first transition series has unchanging Ionization energies.
The group 2 metals have different values of the first ionization energies.
The standard potentials increase in value over time.
The elements are more readily oxidation than hydrogen, with the exception of Cu to Cu2+.
The metals reduce H-21g2 to H+1aq2.
There are more comments on electrode potentials in the chapter.
We think of metals as forming ionic compounds.
This is the case with group 1 and most group 2 metal compounds.
Some metal compounds have significant covalent character.
Transition metal compounds are both ionic and covalent.
In general, compounds with the transition metal in lower oxidation states are essentially ionic, while those in higher oxidation states have covalent character.
As an example, a green ionic solid with a melting point of 1785 degC is called MnO, while a dark red, oily one is called Mn2O7.
The bonding in atoms occurs in polyatomic cations or anions rather than the simple compound that is monatomic ion.
Some transition metals, such as Ni and Pt, can be made by an unusual ability to adsorb gaseous species.
The ability of transition metal ion bonds to serve as catalysts in certain oxidation-reduction reactions seems to account for the possibility of multiple compound with covalent oxidation states.
Complex-ion formation is a distinctive feature of transition metal chemistry and will be explored more fully in Chapter 24.
Catalysis is an essential part of most chemical manufacturing processes, and transition metals are often the key elements in the catalysts used.
Ni is used in the hydrogenation of oils, Pt, Pd, and Rh are used in automobiles, and Fe3O4 is the main component of the catalyst used in the synthesis of ammonia.
Heterogeneous and transition metal catalysts are used.
The reactants, products, and catalyst are all in the same phase and the transition metal is part of a compound.
In heterogeneous catalysis, the catalyst is in a different phase from the reactants or the products, and the catalyst provides a surface on which the reaction occurs.
Heterogeneous catalysis is made use of by the hydrogenation of oils.
The amount of reactants used and the temperature are two of the factors that affect how a catalyst works in a hydrogenation reaction.
A C2H4 molecule is adsorbed onto the metal surface, with electron density being transferred from the p bond in C2H4 to metal atoms in the surface.
H atoms become bonds to carbon atoms, which desorb from the metal surface.
There is a debate about the exact details of the mechanism.
The H-H bond was weakened by the Transition Elements near the C2H4 molecule.
The C2H6 molecule is created when hydrogen atoms are transferred to the carbon atoms in the C2H4 molecule.
Transition metal compounds have a wide variety of colors.
Large numbers of atoms.
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When the metal is placed in a magnetic field.
The growth of domains with favorable orientations may be at the expense of those with unfavorable orientations.
When the object is removed from the magnetic field, the ordering of the domains can persist.
The key factors in ferromagnetism are that the atoms have unpaired electrons and interatomic distances are of just the right magnitude.
If atoms are too large, interactions are weak.
The tendency is for atoms to pair with each other.
The critical factor of atomic size is met in Fe, Co, and Ni.
Some examples are Al-Cu-Mn, Ag-Al-Mn, and Bi-Mn.
The effect of a magnetic field is to align the magnetic moments of individual atoms.
In a ferromagnetic material, the magnetic moments are aligned even in the absence of a magnetic field, but the direction of the alignment varies from one domain to another.
The effect of the magnetic field is to change the orientation of the alignments into one direction.
Most of the observed behavioral differences between the transition and main-group elements can be traced to the orbitals that are most involved in bond formation.
Iron and copper have important uses related to their metallic properties, for example.
The transition metals of groups 1 and 2 and aluminum in group 3 are obtained by procedures developed over many centuries.
There is no single method of metallurgy.
We can show them with the metallurgy of zinc.
Concentration is the percentage of the material mined that is the desired mineral from which a metal is to be removed.
It is necessary to separate the desired material from the waste rock.
Ore particles are attached to air bubbles and then collected in the overflow froth.
The Transition Elements Roasting An Ore converts a metal compound to oxide by heating it to a high temperature.
The commercially important ores for zinc are ZnCO3 and ZnS.
When it is strongly heated, ZnCO31s2, like the carbonates of the group 2 metals, breaks down into ZnO and CO21g2 When heated in air, ZnS(s) reacts with O21g2 and SO21g2.
SO21g2 is converted to sulfuric acid in modern smelting operations.
Carbon, in the form of coke or powdered coal, is used as the reducing agent whenever possible because it is inexpensive and easy to handle.
Both C(s) and CO(g) act as reducing agents.
The temperature above the boiling point of zinc is 1100 degC, where the reduction of ZnO is carried out.
The zinc is a liquid.
Chemical reduction can produce metal that is not pure enough for use.
The metal must be refined.
The refining process is determined by the nature of the impurities.
The zinc is mostly Cd and Pb, which can be removed by the fractional distillation of liquid zinc.
Most of the zinc produced worldwide is refined in a process that combines reduction and refining.
H2SO41aq2 is dissolved in ZnO from the roasting step.
Zn is added to the solution to replace less active metals.
The solution is lyzed.
2 O21g2 could be canceled.
In the overall reaction, zinc is reduced to pure metallic zinc and sulfuric acid is regenerated.
The acid is recycled.
A simple way to purify a solid is to melt it and refreeze it.
The solid that freezes is pure.
The method is not easy because the solid that freezes is wet with unfrozen liquid and thus retains some impurities.
One or more solutes could be in the solid solvent.
The impurities concentrate in the liquid phase between the solid and liquid.
The purer the solid obtained in the second freezing is than in the first, if it is remelted and molten.
A very pure solid product can be produced by repeating the melting and refreezing procedure hundreds of times.
2 PbO1s2 + 2 SO21g2 as reaction.
A metal oxide can be converted into a metal sulfide by roasting.
CO(g) is produced when carbon is used as a reducing agent.
Reduction half-reaction is involved in the deposition of Ag.
The accompanying oxidation half-reaction is not specified and neither is it specified whether this is an electrolysis process or whether silver is displaced by a more active metal.
melting occurs when a heating coil moves up the rod.
Impurities are concentrated in the molten zone.
The portion below the molten zone is purer than the portion above the molten zone.
The rod becomes purer with each passage of the heating coil.
The red line shows the freezing points of solutions.
The blue line shows the composition of the solid.
The blue line is close to the temperature axis in some cases.
The point representing the composition of the solid moves closer to pure A as the melting point increases.
In zone refining the melting/freezing cycles are done continuously.
The end of the rod is cut off.
The process is capable of producing materials with low levels of impurity in them.
The reduction of zinc oxide by carbon is seen as a competition between zinc and carbon for O atoms.
To establish the conditions under which carbon will reduce zinc oxide to zinc, we start by comparing the relative tendencies for zinc and carbon to oxidize.
The tendencies can be assessed through energy changes.
To determine if the reduction of zinc oxide to zinc by carbon is a spontaneously occurring process.
In the neous reaction, we need the value of C/rGdeg for the overall reaction, represented reduction of ZnO with C, below by reversing equation (b) and adding it to equation (a).
We need some data to complete the assessment.
We conclude that the reaction doesn't happen until a temperature of over 1700 degrees is reached.
The temperature at which a chemical reaction can be carried out is not used in the metallurgy of magnesium.
Common variations of the methods previously discussed are worth mentioning.
It is not always necessary to separate metals from one another.
In making alloys with iron, a major use of vanadium, chromium, and manganese is.
Obtaining each metal on its own is not important.
Adding ferrochrome directly to iron will produce one type of steel.
The oxides V2O5 and MnO2 can be isolated.
ferromanganese and ferrovanadium form when iron compounds are added to the oxides.
A mole of gas is lost.
An additional mole of gas forms resulted in a positive value.
The needs of the military and the aircraft industry spurred the development of titanium production.
Steel has a high density of 7.8 g cm-32, making it unsuitable as the structural metal for aircraft.
The advantage of a low density 1d is lost at high temperatures.
Titanium metal can't be produced by reduction of TiO2 with carbon because the metal and carbon react to form titanium carbides.
The metal reacts with air to form TiO2 and TiN.
The metallurgy of titanium has to be done out of contact with air and with an active metal.
A good reducing agent is needed to reduce Ti to Ti.
O2 has to be further treated and alloyed before it can be used.
It takes a week to produce a few tons of Ti.
The TiO2 is placed at the cathode of the cell.
The Ti(IV) is reduced to Ti(s) at the cathode, which is the vessel that holds the electrolytic cell.
The sponge is made of titanium metal.
The copper ores usually contain iron sulfides, which makes it difficult to extract copper from them.
The scheme of metallurgy produces copper contaminated with iron.
Contamination with iron is not a problem for some metals because they are mostly used in the manufacture of steel.
The pure metal of copper is prized for its properties.
Changes to the usual methods are needed to avoid ironcontamination.
Concentration of copper is done by flotation and roasting.
If the temperature is kept below 800 degC, the copper remains as the sulfide.
Reduction of the roasted Ore in a furnace causes it to melt and separate into two layers.
The top layer is a silicate slag formed by the reaction of oxides of Fe, Ca, and Al with SiO2
The remaining iron sulfide is used to make copper.
The air is blown through the furnace after the slag is poured off.
Where high purity is not required, blisters can be used.
The method outlined on page 905 is used for refining blister copper to obtain high-purity copper.
In electrical applications, high-purity copper is essential.
It is suggested that high temperatures are involved.
The metal ion is removed by a liquid.
Water, acids, bases, and salt solutions are Leaching agents.
Oxidation- reduction reactions may be involved.
The solution may be made more concentrated by the separation of the Impurities.
The surface of activated charcoal, ion exchange, and the evaporation of water can be used to remove impurities.
The desired metal is either precipitated in an ionic solid or reduced to the free metal.
In the past, hydrometallurgy has been used to get silver and gold.
In the United States, a typical gold Ore has about 10 g Au per metric ton.
This is followed by the removal of Au from the solution by an active metal.
In one hydrometallurgical process for zinc, a zinc sulfide Ore is washed with a sulfuric acid solution at 150 degC and an oxygen pressure of 7m.
There is no SO21g2 emission in this process.
The roasting process emits SO21g2 instead of mercury in the ZnS Ore, which is retained in the solution.
H2SO41aq2 is regenerated after the Transition Elements ZnSO41aq2 is regenerated.
The H2SO41aq2 is recycled.
The production of zinc from zinc sulfide is described in the text.
In the United States, iron is the most widely used metal from Earth's crust, and for this reason, we slightly more than half of use this section to explore the metallurgy of iron and its principal alloy.
Since ancient times, many technological advances have been made.
This understanding is based on the concepts of thermodynam Waste ics.
Table 23.2 contains a more complete description of the blast furnace reactions.
2 Fe + 3 H2O 1900 degC2 is introduced to remove the impurities from the bottom.
2 Ca31PO4221l2 11200 degC2 are drained off.
Table 23.2 outlines Si + 2 CO 11400 degC2
The blast furnace charge is the solid reactants of ironore, coke, a slag-forming flux, and perhaps some scrap iron.
The proportions can be determined by the composition of the iron Ore.
The purpose of the flux is to maintain the proper ratio of acidic oxides to basic oxides.
Limestone, CaCO3 or dolomite, CaCO # 3 MgCO3 are acidic oxides that dominate most ores.
It has varying amounts of Fe, 3%- 4% C, and other impurities.
When an object undergoes a transmission housing in an automobile, it can experience mechanical or thermal shock.
The first two objectives are accomplished by the reactions that occur.
Reaction time is 22 minutes.
The desired alloying elements are added to the iron after the liquid slag is poured off the reaction vessel.
Steelmaking is undergoing rapid technological changes.
It is now possible to make iron and steel directly from iron Ore in a single step, continuous process at temperatures below the melting point of any of the materials used in the process.
The economic viability of the DRI process depends on the availability of iron and natural gas.
A balanced chemical equation is needed to reduce iron(III) oxide by hydrogen gas.
The properties and uses of the first-row transition metals span a wide range, strikingly illustrating periodic behavior despite the small variation in some of the atomic properties listed in Table 23.1.
The preparation, uses, and reactions of the compounds of these metals show concepts we have previously discussed.
It's not especially rare, but Scandium is an obscure metal.
It's more abundant than many better known metals, including lead, uranium, molybdenum, tungsten, antimony, silver, mercury, and gold.
Scandium production is measured in gram or kilogram quantities, not tons.
The application is in high-intensity lamps.
The pure metal is usually prepared by the electrolysis of a fused mixture.
The Sc3+ ion lacks some of the characteristics of transition metal ion because of its noble-gas electron configuration.
Most of the ion's salts are diamagnetic.
Sc3+ is similar to Al3+ in its chemical behavior, as in the formation of an amphoteric gelatinous hydroxide, Sc1OH23.
The ninth most abundant element is titanium.
The metal has low density, high structural strength, and is resistant tocorrosion.
The first two properties account for its extensive use in the aircraft industry and the third for its uses in the chemical industry: in pipes, component parts of pumps, and reaction vessels.
Titanium is 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 800-273-3217 The metal provides a strong support and the bone bonds directly to the titanium implant, making it a part of the body.
Several compounds of titanium are of particular commercial importance.
Hips, knees, and elbows are all part of TiCl4.
The reaction of naturally occurring rutile 1TiO22 with carbon and Cl21g2 is the usual method of preparing TiCl4.
TiCl4 is a liquid that is odorless.
Ti atoms are used in bond formation in the +4 oxidation state.
Ti is a strong resemblance to the group 14 elements, with some properties and atetrahedral similar to those of CCl4 and SiCl4.
The smoke grenade is a type of smoke grenade in which TiO21s2 is the smoke.
In a similar reaction, TiO21s2 + 4 HCl1g2 other components to produce SiCl4 also fumes in moist air.
Because it's used in paints.
White lead has been displaced by TiO2 in this application.
In glass, ceramics, floor coverings, and cosmetics, TiO2 is used as a paper whitener.
Vanadium is abundant in several dozen ores.
The metallurgy of vanadium is not easy, but it is possible.
Steels containing vanadium are used in springs and high-speed machine tools.
In the conversion of SO21g2 to SO31g2 in the contact method for the manufacture of sulfuric acid, the most important compound of vanadium is the pentoxide, V2O5.
The activity of V2O5 may be linked to the loss of oxygen in the 700 to 1100 degree range.
Vanadium can be found in a variety of oxidation states.