WHAT IS ACIDS, BASES AND INDICATORS? All the elements in nature fall into three classes: metals, non-metals and gases. Non-metals are also sometimes called metalloids. The compounds formed by combination… Read More »ACIDS, BASES AND INDICATORS
EVAPORATION AND BOILING (LIQUID TO GAS) On heating particles gain kinetic energy and move faster. In evaporation and boiling the highest kinetic energy molecules can ‘escape’ from the attractive forces… Read More »EVAPORATION AND BOILING
Chemists are the people who transform the everyday materials around us into amazing things. Some chemists work on cures for cancer while others monitor the ozone protecting us from the… Read More »CAREERS IN CHEMISTRY
Sodium Carbonate (Na2CO3) Popularly known as washing soda or soda ash, sodium carbonate is a commercially important compound. In earlier days, it was obtained from the ash of plants and… Read More »SODIUM HYDROGEN CARBONATE AND SODIUM CARBONATE
What is Carbon monoxide?. Carbon monoxide is an odourless, tasteless and colourless gas, which is insoluble in water. It is extremely poisonous. Under no circumstances must the gas be inhaled… Read More »CARBON (II) OXIDE (CARBON MONOXIDE)
CHEMICAL PROPERTIES OF CARBON The combustion of carbon: Carbon reacts with oxygen to form two oxides, carbon dioxide, CO2, and carbon monoxide CO. The proportions of these two oxides formed… Read More »CHEMICAL PROPERTIES OF CARBON
AMORPHOUS CARBON Apart from diamond and graphite, which are crystalline forms of carbon, all other forms of carbon are amorphous allotropes of carbon. Coke Coke is the amorphous allotrope of… Read More »AMORPHOUS CARBON
What is graphite? Unlike the tetrahedral arrangement of atoms in diamond, the carbon atoms in graphite are arranged in the form of hexagonal rings in layers (Fig.10.2). Each carbon is… Read More »GRAPHITE
DIAMOND What is diamond? Diamond is the purest form of natural carbon. It occurs as small crystals embedded in rocks. These are supposed to have been formed by the crystallization… Read More »DIAMOND
Cathode reactions (reduction) (-) negative cathode where reduction of the attracted positive cations is by electron gain (reduction) to form metal atoms or hydrogen [from Mn+ or H+, n =… Read More »ELECTRODE REACTIONS
Electroplating is a process of depositing a thin layer of a fine and superior metal (like chromium, zinc, nickel, gold etc.) over the article of a baser and cheaper metal… Read More »ELECTROPLATING
However, if the compound is unable to ionise it does not conduct electricity it is called a non-electrolyte. In general, the extent to which an electrolyte can break up into… Read More »ELECTROLYTES AND NON-ELECTROLYTES
Introduction In any chemical reaction, the existing chemical bonds are broken and new chemical bonds are formed. Hence, all chemical reactions are fundamentally electrical in nature since electrons are involved… Read More »EFFECT OF AN ELECTRIC CURRENT ON SUBSTANCES
General Preparation of Salts Salts are generally ionic compounds formed by the reaction of an acid with a base. The preparation of these salts involves the treating of different metals… Read More »SALTS
Bonding in metals Metal atoms have relatively few electrons in their outer shells. When they are packed together, each metal atom loses its outer electrons into a ‘sea’ of free… Read More »BONDING IN METALS
Van Der Waals Forces Intermolecular attractions are attractions between one molecule and a neighbouring molecule. The forces of attraction which hold an individual molecule together (for example, the covalent bonds)… Read More »INTERMOLECULAR BONDING – VAN DER WAALS FORCES
Silicon dioxide Has a high melting point – varying depending on what the particular structure is (remember that the structure given is only one of three possible structures), but around… Read More »THE PHYSICAL PROPERTIES OF SILICON DIOXIDE
THE PHYSICAL PROPERTIES OF GRAPHITE Graphite Has a high melting point, similar to that of diamond. In order to melt graphite, it isn’t enough to loosen one sheet from another.… Read More »THE PHYSICAL PROPERTIES OF GRAPHITE
Diamond Has a very high melting point (almost 4000°C). Very strong carbon-carbon covalent bonds have to be broken throughout the structure before melting occurs. Is very hard. This is again… Read More »THE PHYSICAL PROPERTIES OF DIAMOND
COVALENT BONDING As well as achieving noble gas structures by transferring electrons from one atom to another as in ionic bonding, it is also possible for atoms to reach these… Read More »COVALENT BONDING – SINGLE BONDS