Explain accordingly to Edexcel A Level chemistry syllabus, of alcohol reactions and conditions

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Welcome to our exploration of alcohol reactions according to the Edexcel A Level Chemistry syllabus. Alcohols are versatile organic compounds characterized by the hydroxyl functional group. They are classified into three types based on the carbon atom to which the hydroxyl group is attached. Primary alcohols have the hydroxyl group attached to a carbon with two hydrogen atoms. Secondary alcohols have the hydroxyl group on a carbon with one hydrogen atom. Tertiary alcohols have the hydroxyl group on a carbon with no hydrogen atoms. This classification is important because it determines how alcohols react under different conditions. Let's examine the oxidation of alcohols, a key reaction in the Edexcel syllabus. The oxidation behavior depends on the alcohol class. Primary alcohols can be oxidized to aldehydes if the product is distilled off as it forms, preventing further oxidation. Under reflux conditions with excess oxidizing agent, primary alcohols are oxidized to carboxylic acids. Secondary alcohols are oxidized to ketones, which cannot be oxidized further under these conditions. Tertiary alcohols resist oxidation under normal conditions because they lack a hydrogen atom on the carbon bearing the hydroxyl group. The common oxidizing agents are acidified potassium dichromate or potassium permanganate. With dichromate, you'll observe a color change from orange to green as the chromium is reduced. Dehydration is another important reaction of alcohols in the Edexcel syllabus. This is an elimination reaction where water is removed from the alcohol to form an alkene with a carbon-carbon double bond. The reaction requires concentrated sulfuric acid or phosphoric acid as a catalyst and dehydrating agent. The mixture is heated to around 170 degrees Celsius for ethanol. The mechanism involves three key steps: First, the hydroxyl group is protonated by the acid. Second, water leaves as a good leaving group, forming a carbocation intermediate. Finally, a proton is lost from an adjacent carbon atom to form the carbon-carbon double bond. The overall reaction can be summarized as the conversion of an alcohol to an alkene plus water. This reaction follows Zaitsev's rule, meaning that the major product is the most substituted alkene. Substitution reactions are another important class of alcohol reactions in the Edexcel syllabus. In these reactions, the hydroxyl group is replaced by a halogen atom. The common reagents are hydrogen halides such as HCl, HBr, and HI, or a mixture of sodium or potassium halide with concentrated sulfuric or phosphoric acid. The reaction requires heating, and the reactivity of hydrogen halides follows the order: HI is more reactive than HBr, which is more reactive than HCl. The mechanism involves three key steps: First, the hydroxyl group is protonated. Second, water leaves as a good leaving group, forming a carbocation intermediate. Finally, the halide ion attacks the carbocation to form the haloalkane product. The reactivity of alcohols in substitution reactions follows the order: tertiary alcohols react faster than secondary alcohols, which react faster than primary alcohols. This is due to the increasing stability of the carbocation intermediate in that order.