http://i-chemistry.blogdrive.com/ i-care Sun, 11 Nov 2007 00:35:01 PST http://www.blogdrive.com Copyright 2007. Books Books Books http://i-chemistry.blogdrive.com/archive/14.html Sun, 11 Nov 2007 08:34:15 GMT Soaps and Detergents Soaps are sodium or potassium salts of long chain of carboxylic acids (Fatty acids). Detergents are sodium salts of alkylbenzene sulphonic acid or alkyl hydrogen sulphate. Saponification is hydrolysis of an ester by hot aqueous alkali solution to form an alcohol and sodium (or potassium) salts of Carboxylic acids. The hydrophilic and hydrophobic parts of soap anion work together to remove greasy stains Additives are added to detergents to make the more effective as a cleasing agent Food Additives Food additives are substance added in small amount to... (more) http://i-chemistry.blogdrive.com/comments?id=14 http://i-chemistry.blogdrive.com/archive/13.html Sun, 11 Nov 2007 08:33:17 GMT Evaluating Energy Changes in Chemical Reactions An exothermic reaction gives off heat energy to the surrounding. The temperature of surrounding increase An endothermic reaction absorbs heat energy from the surrounding. The temperature of the surrounding drops. The energy content of reactants is higher than that of the product in exothermic reaction The energy content of product is higher The different of the energy contents between product and reactant is the heat of reaction. Heat of reaction, ¦¤H has a negative sign for exothermic reaction and a positive sign for endothermic... (more) http://i-chemistry.blogdrive.com/comments?id=13 http://i-chemistry.blogdrive.com/archive/12.html Sun, 11 Nov 2007 08:32:01 GMT Redox Reaction Oxidation occurs when there is a gain in oxygen, a loss of hydrogen, a loss of electron pr an increase in the oxidation number of a substance. Reduction occurs when there is a loss of oxygen, a gain in hydrogen, a gain in electrons or a decrease in oxidation number of substance. Oxidation and reduction take place simultaneously in a redox reaction A substance that oxidizes another substance is called an oxidizing agent. Its is reduced in the redox reaction A substance that reduces another substance is called a reducing agent. It is oxidized in the redox reaction The... (more) http://i-chemistry.blogdrive.com/comments?id=12 http://i-chemistry.blogdrive.com/archive/11.html Sun, 11 Nov 2007 08:30:38 GMT Carbon compound Carbon compound are divided into two groups , organic and inorganic compound Organic compound are carbon compounds that a derived or obtained from living or once living things Hydrocarbons are organic compounds containing hydrogen and carbon atoms only. Non-hydrocarbon contains other elements such as nitrogen and oxygen besides hydrogen and carbon. Alkanes Alkanes are saturated hydrocarbon with general formula CnH2n+2, where n= 1,2,3,…. The name of alkanes end with ‘-ane’ The physical properties of alkanes a) The first four members if alkanes exist as... (more) http://i-chemistry.blogdrive.com/comments?id=11 http://i-chemistry.blogdrive.com/archive/10.html Sun, 11 Nov 2007 08:29:16 GMT 10.1 Rate of Reaction Chemical reactions take place at different rates A fast reaction takes a shorter time to complete whereas a slow reaction tale a longer time Rate of reaction Ü ____1_____ Time taken Rate of reaction is determined by measuring how quickly a reactant is used up or how quickly a product is produced over a period of time Rate of reaction = amount of a reactant used up Time taken Rate of reaction = _amount of a product formed ... (more) http://i-chemistry.blogdrive.com/comments?id=10 http://i-chemistry.blogdrive.com/archive/9.html Sun, 11 Nov 2007 08:28:39 GMT Sulphuric acid Sulphuric acid is manufactured in industry through the Contact Process. There are three stages in the Contact Process. Stage 1: Production of sulphur dioxide from sulphur Stage 2: Production of sulphur trioxide from sulphur dioxide at temperature of 450-500 oC , pressure of 2 - 3 atmospheres. The catalyst used is vanadium (V) oxide (optimum condition) Stage 3: Conversion of sulphur trioxide to sulphuric acid Ammonia and Its Salts Ammonia is manufactured on a large scale in the Haber process where nitrogen and... (more) http://i-chemistry.blogdrive.com/comments?id=9 http://i-chemistry.blogdrive.com/archive/8.html Sun, 11 Nov 2007 08:28:01 GMT Salts A salt is formed by the replacement of hydrogen ions in an acid by metallic ions or ammonium ion Soluble salts are prepared from their reaction with acids a) Reaction of acids with alkalis b) Reaction of acid with insoluble metallic oxides or hydroxides c) Reaction of acids with more electropositive metal such as zinc and magnesium (excepts potassium, sodium and calcium) d) Reaction of acids with metallic carbonates. Insoluble salts are prepared by the precipitation method through double decomposition reaction When a hot saturated aqueous solution is... (more) http://i-chemistry.blogdrive.com/comments?id=8 http://i-chemistry.blogdrive.com/archive/7.html Sun, 11 Nov 2007 08:27:15 GMT Acid and Bases An acid is a substance that contains hydrogen ion , H+ , ad the only positive ions in aqueous solution Abase is a substance that react with an acid to give only a salt and water The presence of water is essential for the formation oh hydrogen ion. H+ and hydroxide ions, OH-, in the aqueous solution Strength of Acid and Alkalis All aqueous acid has a sour taste. They show similar chemical properties. a) They have a pH value less than 7 and turn litmus papers from blue to red b) Most dilute acids react with metals (excepts copper, silver and gold) to... (more) http://i-chemistry.blogdrive.com/comments?id=7 http://i-chemistry.blogdrive.com/archive/6.html Sun, 11 Nov 2007 08:26:35 GMT Electrolytes and Non-electrolytes Electrolyte are compound that conduct electricity in a molten state or in an aqueous solution and are decomposed to their constitute elements in the process All electrolyte contain freely moving ions that conduct electricity Non-electrolytes are substance that do not conduct electricity even in a molten state or in an aqueous solution All non-electrolytes do not contain mobile ions. Covalent compounds usually do not conduct electricity because they are made up of neutral molecules. A conductor is a substance which conduct electricity but does not... (more) http://i-chemistry.blogdrive.com/comments?id=6 http://i-chemistry.blogdrive.com/archive/5.html Sun, 11 Nov 2007 08:25:50 GMT Formation of Compound The noble gases are inert and monoatomic because they have stable electronic structure (octet and duplet) Atoms combined together through chemical bonding to achieve stability and to acquire stable electronic structure Two main way of forming chemical bonds between atoms are ionic bond and covalent bonds. Ionic Bond: The Transfer of Electrons Ionic bonds are formed when electrons are transferred from metal atom to non-metal atoms to form positive and negative ions Positive ions (cation) are formed when atoms lose electron. Negative ions (anions) are... (more)