Assertion (A): C6H5CHO On Heating With Dilute NaOH Forms Aldol ...

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• Assertion A C6H5CHO on heating...

AnswerQuestion Answers for Class 12Class 12 BiologyClass 12 ChemistryClass 12 EnglishClass 12 MathsClass 12 PhysicsClass 12 Social ScienceClass 12 Business StudiesClass 12 EconomicsQuestion Answers for Class 11Class 11 EconomicsClass 11 Computer ScienceClass 11 BiologyClass 11 ChemistryClass 11 EnglishClass 11 MathsClass 11 PhysicsClass 11 Social ScienceClass 11 AccountancyClass 11 Business StudiesQuestion Answers for Class 10Class 10 ScienceClass 10 EnglishClass 10 MathsClass 10 Social ScienceClass 10 General KnowledgeQuestion Answers for Class 9Class 9 General KnowledgeClass 9 ScienceClass 9 EnglishClass 9 MathsClass 9 Social ScienceQuestion Answers for Class 8Class 8 ScienceClass 8 EnglishClass 8 MathsClass 8 Social ScienceQuestion Answers for Class 7Class 7 ScienceClass 7 EnglishClass 7 MathsClass 7 Social ScienceQuestion Answers for Class 6Class 6 ScienceClass 6 EnglishClass 6 MathsClass 6 Social ScienceQuestion Answers for Class 5Class 5 ScienceClass 5 EnglishClass 5 MathsClass 5 Social ScienceQuestion Answers for Class 4Class 4 ScienceClass 4 EnglishClass 4 MathsAssertion (A): ${{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{CHO}}$ on heating with dilute NaOH forms aldol condensation product.Reason(R): ${{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{CHO}}$ has no alpha-hydrogen.A.Both A and R are true and R is the correct explanation of AB.Both A and R are true and R is not the correct explanation of A.C.A is true but R is false.D.A is false but R is true.AnswerVerified568.8k+ viewsHint: Aldol condensation is an organic reaction in which enolate ion reacts with a carbonyl compound to form beta-hydroxy ketone or beta-hydroxy aldehyde. This is then followed by a dehydration process to give a conjugated enone. Aldol condensation is an important organic synthesis, to form a new carbon-carbon bond.Complete step by step answer:Mechanism for Aldol condensation reaction:${\text{C}}{{\text{H}}_{\text{3}}}{\text{CHO}}\xrightarrow[{{{\text{H}}_{\text{2}}}{{O,\Delta }}}]{{{\text{NaOH}}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{CH = CHCHO}}$Step 1: Deprotonation of aldehyde by hydroxide ionStep 2: The enolate ion formed in step 1 will add to the unreacted aldehyde.Step 3: The alkoxide ion formed in step 2 will be protonated by water and will form Aldol.Step 4: A small amount of Aldol is converted into enolate ion by the hydroxide ion.Step 5: The enolate ion formed in the above step will lose a hydroxide ion and will form alpha-beta-unsaturated aldehyde. As you can notice in the mechanism of Aldol condensation presence of alpha-hydrogen is compulsory for the reaction to proceed. And when you look at ${{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{CHO}}$, there is no alpha-hydrogen and hence, the given compound will not undergo Aldol condensation.Hence the assertion (A) is incorrect but the reason (R) is correct.So, the correct answer is Option D .Note:Alpha-hydrogens are the hydrogens attached to the carbon atom next to the functional group. Now, as you have seen the presence of alpha-hydrogen is necessary for Aldol condensation. Compounds not having alpha-hydrogens undergo Clasien condensation reaction rather than Aldol condensation. Therefore, ${{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{CHO}}$ will undergo a Claisen condensation reaction.Recently Updated PagesMaster Class 12 English: Engaging Questions & Answers for SuccessMaster Class 12 Business Studies: Engaging Questions & Answers for SuccessMaster Class 12 Economics: Engaging Questions & Answers for SuccessMaster Class 12 Social Science: Engaging Questions & Answers for SuccessMaster Class 12 Maths: Engaging Questions & Answers for SuccessMaster Class 12 Chemistry: Engaging Questions & Answers for SuccessMaster Class 12 English: Engaging Questions & Answers for SuccessMaster Class 12 Business Studies: Engaging Questions & Answers for SuccessMaster Class 12 Economics: Engaging Questions & Answers for SuccessMaster Class 12 Social Science: Engaging Questions & Answers for SuccessMaster Class 12 Maths: Engaging Questions & Answers for SuccessMaster Class 12 Chemistry: Engaging Questions & Answers for Success

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