Why is sulphuric acid not used during the reaction of alcohols with ki

In the presence of sulphuric acid (H 2SO 4), KI produces HI as follows : - 2KI + H 2SO 4 → 2KHSO 4 + 2KI Since H 2SO 4 is an oxidizing agent, it oxidizes HI (produced in the reaction to I 2) as follows: - 2HI + H 2SO 4 → I 2 + SO 2 + H 2O As a result, the reaction between an alcohol and HI to produce alkyl iodide cannot occur. Therefore, sulphuric acid is not used during the reaction of alcohols with KI. Instead, a non-oxidizing acid such as H3PO4 is used in the reaction to get the desired product.

10. 2 Why is sulphuric acid not used during the reaction of alcohols with KI? 10.3 Write structures of different dihalogen derivatives of propane. 10.4 Among the isomeric alkanes of molecular formula C_5H_12 , identify the one that on photochemical chlorination yields (i) A single monochloride. (ii) Three isomeric monochlorides. (iii) Four isomeric monochlorides. (iii) Four isomeric monochlorides.

Q. 4. Account for the following : (i) Sulphuric acid is not used during the reaction of alcohols with KI. (ii) p-methoxybenzyl bromide reacts faster than p-nitrobenzyl bromide with sodium ethoxide to form an ether product. (iii) Organic halogen compounds used as solvents in industry are chlorides rather than bromides and iodides. (iv) Wurtz reaction fails in case of tert-alkyl halides. (v) Alkyl halides are insoluble in water though they contain a polar \( C - X \) bond. (vi) Use of \( CHCl _ \) as anaesthetic is not preferred. asked Jun 3, 2022 in by ( 35 points)

My textbook says that alcohols react with sodium bromide and sulphuric acid to form the corresponding alkyl bromides. At the same time they also mention that sulphuric acid mustn't be used with potassium iodide ($\ce$? Iodide ions are much more powerful reducing agents than bromide ions: $$\ce$$ A quick glance at the reduction potentials tells you that the analogous bromide reaction has a negative reduction potential and is therefore non-spontaneous. [ Thanks for contributing an answer to Chemistry Stack Exchange! • Please be sure to answer the question. Provide details and share your research! But avoid … • Asking for help, clarification, or responding to other answers. • Making statements based on opinion; back them up with references or personal experience. Use MathJax to format equations. To learn more, see our

NCERT Solutions For Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes Read also Topics and Subtopics in NCERT Solutions for Class 12 Chemistry Chapter 10 Haloalkanes and Haloarenes : Section Name Topic Name 10 Haloalkanes and Haloarenes 10.1 Classification 10.2 Nomenclature 10.3 Nature of C–X Bond 10.4 Methods of Preparation of Haloalkanes 10.5 Preparation of Haloarenes 10.6 Physical Properties 10.7 Chemical Reactions NCERT IN TEXT QUESTIONS 10.1 Write structures of the following compounds: (i) 2-Chloro-3-methylpentane (ii) 1-Chloro-4-ethylcydohexane (iii) 4-tert. Butyl-3-iodoheptane (iv) 1,4-Dibromobut-2-ene (v) 1-Bromo-4-sec. butyl-2-methylbenzene. Ans: 10.2. Why is sulphuric acid not used during the reaction of alcohols with KI? Ans: KI is expected to give HI on reacting with H 2SO 4 which will convert alcohols (R – OH) to alkyl iodides (R – I). However, H 2SO 4 is a strong oxidising agent and it oxidises HI formed during the reaction to I 2 which does not react with alcohol. To solve the problem, H2S04 is replaced by phosphoric acid (H3P04) which provides HI for the reaction and does not give I2 as is done by H2S04. 10.3. Write structures of different dihalogen derivatives of propane. Ans: Four isomers are possible. These are : 10.4. Among the isomeric alkanes of mdlecular formula C 5H 12, identify the one that on photochemical chlorination yields (i) A single monochloride. (ii) Three isomeric monochlorides. (iii) Four isomeric monochlorides. Ans: 10.5. Draw the...