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Copper is extracted from its principal ore copper pyrites (CuFeS 2 ). The ore is concentrated by froth flotation process. The concentrated ore is roasted in a reverberatory furnace when the following reactions occur.  1. The volatiles like sulphur and arsenic escape as gases     S + O 2 --------------> SO 2 4AS + 3O 2 --------------->2AS 2 O 3  2. Copper pyrites is converted to a mixture of Cu 2 S and FeS     2CuFeS 2 + O 2 ---------------> Cu 2 S + 2FeS + SO 2 3. The sulphides of Cu and Fe are partially oxidized  2Cu 2 S + 3O 2 <=======> 2Cu 2 O + 2SO 2  2FeS + 3O 2 <========> 2FeO + 2SO 2 Smelting in extraction of copper   The roasted ore mixed with silica as flux is heated in a blast furnace by a blast of hot air. Most of the FeO is removed as a slag and a molten mixture of Cu 2 S and FeS called matte, get collected in the hearth of the furnace.     ...

The chemical properties of alcohols and phenols are mainly due to the presence of the hydroxyl functional group. The presence of the aromatic benzene ring provides some characteristic chemical reactions for phenols. The reactions of -OH groups in alcohols and phenols may be divided into two classes. 1. Reaction involving cleavage of O-H bond and 2. Reaction involving cleavage of carbon - oxygen (C-O) bond The reaction involving cleavage of O-H bond consist of 1. Reaction with Metals 2. Reaction with alkali 3. Reaction with carboxylic acids (Esterification) The reaction involving cleavage of carbon - oxygen (C-O) bond consist of 1. Reaction with hydrogen halides 2. Reaction with phosphorus halides and SOCl 2 3. Dehydration   4. Oxidation   5. Dehydrogenation

When the vapours of an alcohol are passed over copper catalyst heated at 573K. it undergoes dehydrogenation (loss of hydrogen or oxidation). The product formed depends on the alcohol and hence this reaction is also used to distinguish the three classes of alcohols. When the vapours of  a primary alcohol are passed over copper heated at 573K, the correspondingaldehyde is formed. When the vapours of a secondary alcohol are passed over copper heated at 573K, the corresponding ketone is formed. Tertiary alcohol when reacted with copper catalyst at 573K are not dehydrogenated but undergoes dehydration to give the corresponding alkene.