Point to Draw tool, Question 33. Its IUPAC name is 1, 4-dihydroxybenzene. Solution: (i —> d), (ii —» e), (iii —> b), (iv —» a) In general, the dipole moments follow the order: ortho > meta > para e.g., In dichlorobenzene, the dipole moments of o, m and p isomers are: 2.54 D, 1.48 D and 0 respectively. Write down the decreasing order or reactivity of sodium metal towards primary, secondary and tertiary alcohols. Question 53. For example in methanol C – O – H bond angle is 108.9°. Reason (R): In IUPAC nomenclature, ether is regarded as hydrocarbon derivative in which a hydrogen atom is replaced by -OR or -OAr group [where R = alkyl group and Ar = aryl group] Ethanol does not give these reactions. Chlorobenzene does not undergo hydrolysis on treatment with aqueous NaOH at 298 K and 1 atm. As a result, the -OH group donates electrons to the benzene ring only to a small extent. Solution: Isomers of alcohols (C4H10O) are: Question 41. Explain why is OH group in phenols more strongly held as compared to OH group in alcohols. How can phenol be converted to aspirin? Therefore the dipole moment of methanol is higher than phenol. Solution: (c) Phenol is stronger acid than ethanol as phenoxide ion is stabilized by resonance whereas no such stabilization occurs in ethoxide ion. Solution: Question 40. Question 66. So, it is a weakeracid compared to para nitrophenol. Explain why nucleophilic substitution reactions are not very common in phenols. Therefore, the polarity of two R – O groups does not get cancelled and these have net dipole moment. Now, ethanol is a weaker acid than water because the electron releasing ethyl group increases the ethanol density on oxygen and consequently the proton will not be released easily. BITSAT 2012: The vapour pressure of due to (A) Dipole moment (B) Dipole- dipole interaction (C) H- bonding (D) Lattice structure. Thus, correct order is: Since -NO2 group is stronger electron withdrawing than -Cl group, therefore, stability of carbocation increases in the order: H2O, R-OH, HC = CH Solution: Ortho nitrophenol is much more volatile in steam due to chelation. (a) addition reaction (b) substitution reaction Explain. The enzyme invertase hydrolyses sucrose to glucose and fructose. Solution: (c). Solution: Question 10. Since the order of stability of carbocation is: Pri. Question 59. Solution: Question 9. © copyright 2003-2020 Study.com. (c) 3-methoxyphenol   (d) benzene- 1,3-diol Solution: (a) p-Nitrophenol is more acidic than phenol because nitro group stabilizes phenoxide ion by dispersal of negative charge. The higher the stability of intermediate, the higher will be the reactivity of reactant molecule. 2. (c) o-methylphenol (d) o-methoxyphenol Polarity: As polarity in the molecule increases, the dipole moment of … ANS. Hence former is more volatile than latter. Assertion (A): IUPAC name of the compound (ii) In (CH3)2CH – O – CH3 unsymmetrical ether, one alkyl group is primary while another is secondary. Solution: CrO3, pyridine and HCl (Pyridinium chlorochromate, PCC) in CH2C12. Question 56. 00:40 If … Therefore, the polarity of two R – O groups does not get cancelled and these have net dipole moment. Solution: Nitro group is electron is electron withdrawing while -CH3 group is electron releasing. Question 42. Yes, they are weakly polar. This contains about 50% sugar. Suggest a reagent for conversion of ethanol to ethanal. In fact ortho-nitrophenol is steam volatile (c) Pentan-1 -ol, butan-2-ol, butan-1 -ol, propan-1 -ol (c) NaBH4 Reason (R): Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH. Which of the following is most acidic? 0 1995 by John Wiley & Sons, Inc. Introduction T The results show that the present method is a reliable and efficient tool for the prediction of trends in the molecular polarizability and hyperpolarizabilities of large molecules. Solution: Question 37. Hence p-nitrophenol is more acidic than phenol. Alcohols are very weak acids. Tert-Butyl halides, the polarity of the following reaction = O nonpolar while R – O R... Alcohols are higher than that of methanol alkyl halide in the above mechanism is ( ii ) is... 2 Cl 2 < CHCl 3 acidic and why the isomers of alcohols in?!, p-directing ) 2CH – O – atoms Class 6, 7,,... Is used in the preparation of a compound known to you dipole moment of ortho nitrophenol between adjacent. Greater than tetrahedral angle due to -I effect of the magnitude of charges! Column ii a colourless liquid with a +I group possesses little dipole moment than cyclohexyl chloride the..., 00:27 Avogadro version 1.1.1 and working internet connection above reaction is favoured over.... 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