Tagged: chemistry

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...

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...

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...

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...

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...

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...

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...

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...

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...

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-...

MILLENNIUM DEVELOPMENT GOALS

MEANING OF MDG The Millennium Development Goals (MDG) are eight international development goals that were officially established following the millennium summit of the United Nations in 2000, following the adoption of the United Nations...

INTRODUCTION TO CHEMISTRY

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...