The Equations Involved with The Transition Elements

Introduction

The term ‘transition metals’ is mainly used to define any element in the d-block of the periodic table, this involves groups 3 to 12. A transition metal is an element whose atom possesses a partially filled d subshell, or it can give rise to cations having an incomplete d subshell. Some of the more commonly known transitional metals include titanium, iron, manganese, nickel, copper, cobalt, silver, mercury and gold. Three of the most common elements are those of iron, cobalt and nickel as they are the only elements that are known to produce a magnetic field. There are various different properties identified in the transition elements that are not found in other elements, as a result of their partially filled d shell.

Examples of Transition Elements

Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Yttrium, Zirconium, Niobium, Molybdenum, Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium, Lanthanum, sometimes (often considered a rare earth, lanthanide), Hafnium, Tantalum, Tungsten, Rhenium, Osmium, Iridium, Platinum, Gold, Mercury, Actinium, sometimes (often considered a rare earth, actinide)Rutherfordium, Dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Copernicium presumably is a transition metal.

Transition Metal Properties

The transition metals are the elements that we normally think of when we imagine a metal. These elements possess some properties in common with each other:

• They are good conductors of heat and electricity.

• The transition metals are malleable (they can be easily hammered into different shapes or bent).

• These metals tend to be very hard in nature.

• Transition metals look shiny and metallic. Majority of the transition metals are grayish or white (such as iron or silver), but gold and copper possess colors that are not seen in any other element in the periodic table.

• The transition metals, represents a group that have high melting points. One of the common exceptions is mercury, it is liquid at room temperature. These elements also have high boiling points.

• The d orbitals of the transition elements get progressively filled as we move from left to right across the periodic table. As the subshell is not filled, atoms of the transition metals should have positive oxidation states and also show more than one oxidation state. As seen in iron it mainly carries a 3+ or 2+ oxidation state. Copper might possess a 1+ or 2+ oxidation state. The positive oxidation state refers to the transition metals basically form ionic or partially ionic compounds.

• Atoms of these elements possess low ionization energies.

• Transition metals form colored complexes, thus their compounds and solutions may be colorful. The complexes split the d orbital into two different energy sublevels so that they can absorb specific wavelengths of light. Due to the different oxidation states, it becomes possible for one element to produce complexes and solutions in a wide range of colors.

• As the transition metals are reactive, they are not as reactive as elements belonging to the alkali metals group.

• Many transition metals are able to form paramagnetic compounds.

Isolation of Silver

Silver generally occurs in large form but more frequently in veins and related deposits. At one time, panning was believed to be an effective method of isolating both silver and gold nuggets. Because of their low reactivity, these metals, and a few others, are formed in deposits as nuggets. The discovery of platinum was possible due to the Spanish explorers in Central America, as they have mistaken platinum nuggets for silver. When the metal is no longer in the form of nuggets, it is mainly useful to employ a process known as hydrometallurgy to separate silver from its ores. Hydrology includes the separation of metal from a mixture by first converting it into soluble ions and then extracting and reducing them in order to precipitate the pure metal. In the presence of air, alkali metal cyanides generally form the soluble dicyanoargentate(I) ion,  [Ag(CN)2]− , from silver metal or silver-containing compounds like those of Ag2S and AgCl. This can be represented by the equations which is written as follows:

4Ag(s)+8CN(aq)+O2(g)+2H2O(l)⟶4[Ag(CN)2](aq)+4OH(aq)

2Ag2S(s)+8CN(aq)+O2(g)+2H2O(l)⟶4[Ag(CN)2](aq)+2S(s)+4OH(aq)

AgCl(s)+2CN(aq)⟶[Ag(CN)2](aq)+Cl(aq)

The silver gets precipitated from the cyanide solution due to the addition of either zinc or iron(II) ions, that serves as the reducing agent:

2[Ag(CN)2](aq)+Zn(s)⟶2Ag(s)+[Zn(CN)4]2(aq)

Isolation of Copper

The most vital ores of copper comprises copper sulfides (like those of covellite, CuS), however copper oxides (like tenorite, CuO) and copper hydroxycarbonate [like malachite, Cu2(OH)2CO3] can be found sometimes. For the production of copper metal, firstly the concentrated sulfide ore is roasted to remove part of the sulfur as sulfur dioxide. The remaining mixture, which comprises  Cu2S, FeS, FeO, and SiO2, is mixed with limestone that acts as a flux (it refers to a material that helps in the removal of impurities), and is then heated. Molten slag which is formed as the iron and silica is removed by Lewis acid-base reactions:

CaCO3(s)+SiO2(s)⟶CaSiO3(l)+CO2(g)

FeO(s)+SiO2(s)⟶FeSiO3(l)

In these reactions, the silicon dioxide acts as a Lewis acid that accepts a pair of electrons from the Lewis base (i e. the oxide ion). Reduction of the Cu2S that remains after the process of smelting is accomplished by blowing air through the molten material. The air then converts a part of the Cu2S into Cu2O. As soon as copper(I) oxide is formed, it gets reduced by the remaining copper(I) sulfide to form metallic copper:

2Cu2S(l)+3O2(g)⟶2Cu2O(l)+2SO2(g)

2Cu2O(l)+Cu2S(l)⟶6Cu(l)+SO2(g)

The copper which is obtained by this way is known as blister copper due to its characteristic appearance, which is basically due to the air blisters it contains. This impure copper is then casted into large plates that can be further used as anodes in the electrolytic refining of the metal.

Conclusion

The transition elements are the largest group of elements that are present on the periodic table, and they are situated in the middle of the table. However, the two rows of elements below, the main body of the periodic table (lanthanides and actinides) are subsets of these metals. These elements are known to be “transition metals” since their atoms’ electrons transition to filling the d subshell or d sublevel orbital. As a result, transition metals are also referred to as d-block elements.