HYDROGEN IN CHEMISTRY
Introduction Hydrogen is a chemical element with the symbol H and atomic number 1. It is the lightest and most abundant element in the universe, constituting roughly 75% of its elemental mass. Hydrogen is a nonmetal and is placed in…
AMMONIUM SALTS
Ammonium salts are prepared by dissolving ammonia in the appropriate acid or neutralising aqueous ammonia with the appropriate acid. The ammonium salts are then separated out of the solution by crystallisation and not by evaporation because they are heat-liable. e.g.…
OXIDES
Oxides are binary compounds formed when elements combine with oxygen. Binary compounds are compounds containing two elements only. Oxides are classified into several groups, namely, acidic oxides, basic oxides, amphoteric oxides, neutral oxides and higher oxides. 1) Acidic oxides: These…
IODINE
Iodine was discovered in 1812 by Courtois. Iodides occur in minute quantities in sea water. They are also found as organic compounds in some sea weeds and as deposits of sodium (NaIO3)and calcium trioxoiodates (V), (Ca (IO3)2) in association with…
GRAPHITE
Graphite exists as black, slippery, hexagonal crystals. The carbon atoms in graphite, form flat layers, and are joined together by strong covalent bonds. These layers are arranged in parallel, one above the other, with weak intermolecular forces operating in-between the…
INTRODUCTION TO CARBON
Carbon occurs naturally as diamond and graphite. It also occurs in an impure form as coal and in the combined state as carbon (IV) oxide, natural gas, petroleum and wood. Other sources of carbon are mineral deposits of metallic trioxocarbonates…
DIAMOND
Diamond is the purest form of naturally occuring carbon. It is found as colourless, lustreless solids which can be transformed into brilliant gems. It consists of an array of bonded atoms. No discrete molecules can be distinguished. Diamond crystal is…
OZONE
Ozone is an unstable triatomic molecule of oxygen. In 1866, J. Soret, demonstrated that ozone was an allotrope of oxygen. Ozone is formed from atmospheric oxygen by lightning flashes. Small fractions of ozone are also formed around electrical machinery when…
OCTANE NUMBER
Octane number (octane rating) is a measure of the performance of petrol in the engine and the rating depends on the percentage composition of branched chain (iso-octane) to straight chain (n – pentane) hydrocarbons in the fuel. Petrol consists of…
CRACKING AND REFORMING
CRACKING Cracking is the process of further treatment of crude oil fractions in which bigger hydrocarbon fractions are broken down into smaller hydrocarbon fractions. It consists of heating the hydrocarbons in the C 15- and- above range under high pressure…
INTRODUCTION TO CHEMISTRY
Chemistry may be defined as the science that is concerned with the composition and the structure of matter, and with the forces that hold the structures together. Chemistry as a science has, as its primary objectives, the determination of the…
ETHICAL, LEGAL AND SOCIAL ISSUES IN CHEMISTRY
The study of chemistry has brought tremendous, positive development to the world and to Nigeria in particular. Chemistry has contributed greatly towards providing our basic needs and improving the quality of our life. For example, the provision of clothing, housing,…
Study Guide
