[Chemistry Class Notes] on Aluminium Pdf for Exam

Aluminum (Al), also written aluminium, is a light silvery white metal in the periodic table’s major Group 13 (IIIa, or boron group). Aluminum is the most abundant metallic element (the aluminium element) in the Earth’s crust and the most prevalent nonferrous metal. Aluminum is never found in its metallic form in nature due to its chemical activity, but its compounds can be found to various extents in almost all rocks, vegetation, and animals.

The aluminum atomic number is 13, the aluminium symbol is Al and Al chemical name. Let us look at more detailed information on the aluminium structure, uses properties and compounds and more from this article.

Physical and Chemical Properties

Aluminum, with the aluminium symbol, Al, is concentrated in the outer 16 km (10 miles) of the Earth’s crust, where it makes up around 8% of the total weight; only oxygen and silicon come close. Aluminum is derived from the Latin word alumen, which refers to potash alum (KAl(SO4)212H2O), also known as aluminium potassium sulphate.

The Chemical Properties of Aluminum Are as Follows.

Aluminium Structure

The aluminium structure is represented below.

Occurrence and History

Aluminum is found as aluminosilicates in feldspars, feldspathoids, and micas in igneous rocks; as clay in soil generated from them; and as bauxite and iron-rich laterite after further weathering. The main aluminium resource is bauxite, which is a combination of hydrated aluminium oxides. Emery (corundum) is a crystalline aluminium oxide found in a few igneous rocks that is mined as a natural abrasive or in finer forms as rubies and sapphires. Other gemstones that include aluminium include topaz, garnet, and chrysoberyl. Alunite and cryolite are some of the many other aluminium minerals that have commercial use.

People in Mesopotamia were manufacturing beautiful pottery from an aluminium compound clay before 5000 BCE, while Egyptians and Babylonians used aluminium compounds in various chemicals and medicines about 4,000 years ago. Pliny refers to alumen, now known as alum, an aluminium compound widely used to fix dyes in fabrics in the ancient world. Chemists like Antoine Lavoisier recognised alumina as a potential metal source in the latter half of the 18th century.

Danish physicist Hans Christian Oersted obtained crude aluminium in 1825 by reducing aluminium chloride with potassium amalgam. Sir Humphry Davy, a British chemist, had already termed the aluminium element after electrolyzing fused alumina (aluminium oxide) and had made an iron-aluminum alloy in 1809; the word was eventually adjusted to aluminium in England and some other European countries. Using potassium metal as a reducing agent, German chemist Friedrich Wöhler created aluminium powder (1827) and tiny globules of the metal (1845), from which he was able to discover some of its properties.

The public first saw the new metal (1855) during the Paris Exposition, around the same time that it became available (in small quantities at a high cost) through the sodium reduction of molten aluminium chloride via the Deville process.

When electricity became more readily accessible and cheap, Charles Martin Hall in the United States and Paul-Louis-Toussaint Héroult in France almost simultaneously discovered (1886) the modern method of commercially producing aluminium: electrolysis of purified alumina (Al2O3) dissolved in molten cryolite (Na3AlF6). During the 1960s, aluminium replaced copper as the world’s leading producer of nonferrous metals.

This is the detailed information on the occurrence and history of aluminium.

Uses of Aluminium and Properties

The uses, properties and compounds of aluminum are explained here.

Small amounts of aluminium are added to certain metals to improve their qualities for specific uses of aluminium, such as aluminium bronzes and most magnesium-base alloys; or moderate amounts of other metals and silicon are added to aluminium in aluminum-base alloys. Aircraft construction, building materials, consumer durables (refrigerators, air conditioners, kitchen utensils), electrical conductors, and chemical and food-processing equipment all utilize the metal and its alloys.

Commercial aluminium (99 to 99.6% pure) with modest concentrations of silicon and iron is robust and strong; pure aluminium (99.996%) is soft and weak. Aluminum is a ductile and malleable metal that may be drawn into wire or rolled into thin foil. The metal has a density of about one-third that of iron or copper. Aluminum is highly corrosion-resistant, while being chemically active, because it creates a thick, strong oxide film on its surface when exposed to air.

Aluminum is a great heat and electrical conductor. It has half the heat conductivity of copper and two-thirds the electrical conductivity. It forms a face-centered cubic aluminium structure when it crystallises. Aluminum-27 is the stable isotope of all natural aluminium. Aluminum oxide and hydroxide, as well as metallic aluminium, are nontoxic.

Most dilute acids attack aluminium slowly, while concentrated hydrochloric acid dissolves it quickly. Concentrated nitric acid, on the other hand, may be transferred in aluminium tank cars since it neutralises the metal. Alkalies such as sodium and potassium hydroxide attack even very pure aluminium to produce hydrogen and the aluminate ion. Finely divided aluminium will burn in carbon monoxide or carbon dioxide with the development of aluminium oxide and carbide if ignited, however aluminium is inert to sulphur at temperatures up to red heat due to its high affinity for oxygen.

By using emission spectroscopy, aluminium can be detected in quantities as low as one part per million. Aluminum can be quantified as an oxide (aluminum formula Al2O3) or as a derivative of the organic nitrogen compound 8-hydroxyquinoline (aluminum formula 8-hydroxyquinoline). Al(C9H6ON)3 is the molecular aluminum formula of the derivative.

Compounds

Aluminum is generally trivalent. However, a few gaseous monovalent and bivalent compounds have been produced at high temperatures (AlCl, Al2O, AlO). The configuration of the three outer electrons in aluminium is such that the bare ion, Al3+, generated by the loss of these electrons is known to occur in a few compounds (e.g., crystalline aluminium fluoride [AlF3] and aluminium chloride [AlCl3]).

However, because the energy required to form the Al3+ ion is so large, it is usually more energy efficient for the aluminium atom to form covalent compounds via sp2 hybridization, as boron does. Hydration can stabilise the Al3+ ion, and the octahedral ion [Al(H2O)6]3+ can be found in aqueous solution and in a variety of salts.

A multitude of aluminium compounds are used in a wide range of industries. Alumina, which is found naturally as corundum, is also mass-produced in enormous amounts for use in aluminium metal, insulators, spark plugs, and other products. Alumina develops a porous aluminium structure when heated, allowing it to absorb water vapour. This type of aluminium oxide, known as activated alumina in the industry, is used to dry gases and liquids. It also acts as a carrier for numerous chemical reaction catalysts.