Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance.

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Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance. ... D. A is incorrect but R is correct

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Description : Alcohols are easily protonated than phenols. Justify.

Last Answer : Ans. In phenols lone pair of electrons on the oxygen atom are delocalised over the benzene ring due to resonance and hence are not easily available for protonation. In contrast in alcohols, ... oxygen atom are localized due to absence of resonance and hence are easily available for protonation. 

Description : Phenol has smaller dipole moment than methanol. (OR) Why are dipole moments of phenols smaller than dipole moments of alcohols ?

Last Answer : Due to electron-withdrawing effect of the benzene ring, the C — O bond in phenol is less polar but in case of methanol due to electron-donating effect of — CH3 group, C — O bond is more polar.

Description : (A) Allyl free radical is more stable than simple alkyl free radical. (R) The allyl free radical is stabilized by resonance.

Last Answer : (A) Allyl free radical is more stable than simple alkyl free radical. (R) The allyl free radical is ... IF (A) is incorrect but (R) is correct.

Description : Phenols do not undergo substitution of the — OH group like alcohols. Explain.

Last Answer : The C — O bond in phenols has some double bond character due to resonance and hence cannot be easily cleaved by a nucleophile. In contrast, the C — O bond in alcohols is a pure single bond and hence can be easily cleaved by a nucleo phile.

Description : Phenols can be easily distinguished from alcohols because (a) phenols are soluble in NaOH, but alcohols are not (b) alcohols are soluble in NaOH, but phenols are not (c) phenols are soluble in NaHCO3, but alcohols are not (d) alcohols are soluble in NaHCO3, but phenols are not

Last Answer : phenols are soluble in NaOH, but alcohols are not

Description : Which group forms the strongest H-bonds to water molecules? (a) Alcohols (b) Ethers (c) Phenols (d) All equally strong

Last Answer : Phenols

Description : Why does a H+ ion attacking a carbon-carbon double bond add to the carbon with the least number of substituents? (a) the reaction is resonance stabilized. (b) the hybrid geometry favors this ... tends to attack stable centers of negative charge. (d) a more stable carbonium ion is generated.

Last Answer : a more stable carbonium ion is generated.

Description : Which of the following is not a correct statement concerning the FriedelCrafts acylation of benzene? (a) An alkyl group substitutes for a hydrogen. (b) The benzene ring attacks an acylium ion. (c) The acylium ion is resonance stabilized. (d) The acylium ion is often produced from an acyl chloride.

Last Answer : An alkyl group substitutes for a hydrogen

Description : Assertion (A): Alkyl aryl ethers on reaction with HI give alkyl iodide phenols Reason (R): Aryl - oxygen bond is weaker than alkyl oxygen bond

Last Answer : Assertion (A): Alkyl aryl ethers on reaction with HI give alkyl iodide phenols Reason (R): Aryl - oxygen ... is false D. A is false but R is true

Description : Secretion of gastrin is evoked by (A) Entry of food into stomach (B) Vagal stimulation (C) Lower aliphatic alcohols (D) All of these

Last Answer : Answer : D

Description : Aliphatic primary amines react with cold nitrous acid to form (a) Alcohols (b) Diazonium salts (c) Nitriles (d) Nitroalkanes

Last Answer : Alcohols

Description : Assertion: Intermolecular dehydration is not useful for the perparation of unsymmetrical ethers from primary alcohols Reason: The reaction leads to a

Last Answer : Assertion: Intermolecular dehydration is not useful for the perparation of unsymmetrical ethers from primary ... . Assertion is false, Reason is true

Description : Assertion (A): Dehydration of alcohols can be carried out with Conc `H_(2)SO_(4)` but not with conc HCl Reason (R): `H_(2)SO_(4)` is dibasic while HCl

Last Answer : Assertion (A): Dehydration of alcohols can be carried out with Conc `H_(2)SO_(4)` but not with conc HCl ... R is false D. A is false but R is true

Description : The greater acidity of carboxylic acids compared to alcohols arises primarily from : (a) the electron-donating effect of the hydroxyl group (b) the electron-withdrawing effect of the carboxyl ... of α-hydrogens of carboxylic acids (d) the resonance stability associated with the carboxylate ion

Last Answer : the resonance stability associated with the carboxylate ion

Description : Assertion: The O - O bond lengths in ozone molecule are intermediate between single and double bonds. Reason: `O_(3)` molecule is a resonance hybrid.

Last Answer : Assertion: The O - O bond lengths in ozone molecule are intermediate between single and double bonds. ... I is not correct and Statement-II is correct

Description : Why are amines always less acidic than comparable alcohols?

Last Answer : Ans.--- Amines are less acidic than alcohols because of oxygen higher electronegative & smaller size. Therefore O-H breakes easily than N-H bond. 

Description : Members of which of the following classes of compounds generally produce acidic solutions when dissolved in water? w) metal oxides x) nonmetal oxides y) alcohols z) aldehydes

Last Answer : ANSWER: X -- NONMETAL OXIDES

Description : Ortho and paranitrophenols are more acidic than phanel. Draw the resonance structures of the corresponding phonoxide ion.

Last Answer : Ans:- Electronwithdrawal by nitro group makes the plenoxide ion more resonance stabilized and so the strength of phenel increases.

Description : Assertion :- In acidic medium, equivalent weight of `K_(2)Cr_(2)O_(7)` is equal to `294//6`. Reason :- In acidic medium, `Cr_(2)O_(7)^(-2)` is reduced

Last Answer : Assertion :- In acidic medium, equivalent weight of `K_(2)Cr_(2)O_(7)` is equal to `294//6`. ... is False. D. If both Assertion & Reason are False.

Description : Assertion :- Equivalent weight of `KMnO_(4)` in acidic medium is `M//5` (M=molecular weight) while in basic medium, it is equal of M/3. Reason :- In a

Last Answer : Assertion :- Equivalent weight of `KMnO_(4)` in acidic medium is `M//5` (M=molecular weight) ... False. D. If both Assertion & Reason are False.

Description : Phenol is acidic because of (a) Resonance (b) Electromeric effect (c) Inductive effect (d) Peroxide effect

Last Answer : Resonance

Description : A country with a high rate of population growth took measures to reduce it. The figure below shows age-sex pyramids of populations A and B twenty years apart. Select the correct interpretation about them. ... the growth rate. (d) A is more recent and shows slight reduction in the growth rate.

Last Answer : (d) “A” is more recent and shows slight reduction in the growth rate.

Description : after its political system stabilized, what was south africa’s government able to do?

Last Answer : govern a state or community

Description : The pH of body fluids is stabilized by buffer systems. The compound which will be the most effective buffer at physiologic pH is (A) Na2HPO4 pKa = 12.32 (B) Na2HPO4 pKa=7.21 (C) NH4OH pKa = 7.24 (D) Citric acid pKa = 3.09

Last Answer : Answer : B

Description : α-helix is stabilized by (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds

Last Answer : Answer : A

Description : (2) stabilise the colloid and prevent crystallisation Explanation: Gelatine, being a colloid, has the property of preventing crystallization. In ice lollies and icecream this is demonstrated by the formation ... does not become grainy or sandy due to the slow crystallisation of lactose with time.

Last Answer : Glycol is added to aviation gasoline because it - (1) reduces evaporation of petrol (2) increases efficiency of petrol (3) prevents freezing of petrol (4) reduces consumption of petrol

Description : Which one of the following rollers is suitable for soil-cement stabilized road construction? (a) Vibratory roller (b) Sheepfoot roller (c) Pneumatic roller (d) Smooth wheel roller

Last Answer : (c) Pneumatic roller

Description : Explain why nucleophilic substitution reactions are not very common in phenols.

Last Answer : Explain why nucleophilic substitution reactions are not very common in phenols.

Description : Phenols does not react with

Last Answer : Phenols does not react with A. sodium bicarbonate B. sodium hydroxide C. potassium hydroxide D. ferric chloride

Description : The smell of fat turned rancid is due to (A) Presence of vit E (B) Presence of quinones (C) Phenols (D) Volatile fatty acids

Last Answer : Answer : D

Description : Protein is a polymer of (A) Sugars (B) Phenols (C) Amino acids (D) Carboxylic acids

Last Answer : Answer : C

Description : Phenols are added in gasoline to (A) Improve the octane number (B) Act as an antioxidant (C) Reduce its viscosity (D) Increase its pour point

Last Answer : (B) Act as an antioxidant

Description : While separating a mixture of ortho and para-nitro phenols by steam distillation, name the isomer which will be steam volatile. Give reasons.

Last Answer : In o-nitrophenol, there is intramolecular hydrogen bonding as follows : In p-nitrophenol, there is intramolecular hydrogen bonding as follows :   Due to intermolecular H ... -nitrophenol. Hence o-nitraphenol due to its lower b. p. is steam volatile while pnitrophenol is not.

Description : Which one of the following compounds form zwitterions? (a) carbonyl compounds (b) amino acids (c) phenols (d) heterocyclic compounds

Last Answer : amino acids

Description : Which statement about the structure of benzene is not true? (a) The two Kekule structures of benzene are in equilibrium. (b) The carbon-carbon bond lengths in benzene are greater than the carbon- ... (d) The stability of benzene ring is much greater than the stability of 1,3,5- cycloheptatriene

Last Answer : The two Kekule structures of benzene are in equilibrium

Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity

Description : In low temperature carbonisation (as compared to high temperature carbonisation) of coal (A) Ammonia yield is more (B) Aliphatic tar is produced (C) Free carbon in tar is more (D) All (A), (B) and (C

Last Answer : (B) Aliphatic tar is produced

Description : What is Aliphatic Amin ?

Last Answer : The amine produced when ammonia ( NH 3) to hydrogen ( H) atoms are replaced by aliphatic hydrocarbon radicals such as alkyl radicals is called aliphatic amines .

Description : What is the difference between aliphatic compounds and aromatic compounds ?

Last Answer : aliphatic compounds 1. Aliphatic compounds are mainly free-chain. 2. Aliphatic compounds can be saturated or unsaturated. 3. Aliphatic compounds have low carbon content. 4. Replacement reactions ... compounds. 5. Aromatic halides are relatively less active. . Aromatic hydroxy compounds are acidic.

Description : What is aliphatic hydrocarbon ?

Last Answer : Hydrocarbons without aromatic properties (without circular structure) are called aliphatic hydrocarbons. Such as methane , ethane.

Description : What is aliphatic compound ?

Last Answer : Organic compounds that have free chains of carbon atoms in their molecules are called aliphatic compounds. Such as: CH4, CH3-CH3, CH3-CH2-OH

Description : Two aliphatic aldehydes P and Q react in th presence of aqueous `k_(2)CO_(3)` to give compound R, which upon treatment with HCN provides compound S. O

Last Answer : Two aliphatic aldehydes P and Q react in th presence of aqueous `k_(2)CO_(3)` to give compound R, which ... shown below: The compound S is B. C. D.

Description : Two aliphatic aldehydes (P) and (Q) react in the presence of aqueous `K_(2)CO_(3)` to give compound (R ) which upon treatment with HCN gives compound(

Last Answer : Two aliphatic aldehydes (P) and (Q) react in the presence of aqueous `K_(2)CO_(3)` to give compound (R ) ... (P) and (Q), respectively, are: B. C. D.

Description : The correct sequence regarding base strength of aliphatic amines in aqueous solution is:

Last Answer : The correct sequence regarding base strength of aliphatic amines in aqueous solution is: A. `R_(3)N gt R_(2) NH gt ... gt R_(2)NH gt R_(3)N gt NH_(3)`

Description : What are aliphatic hydrocarbons?

Last Answer : Aliphatic hydrocarbons are not aromatic compounds.

Description : Xanthoproteic test is positive in proteins containing (A) Sulphur amino acids (B) α-Amino acids (C) Aromatic amino acids (D) Aliphatic amino acids

Last Answer : Answer : C

Description : Wax used for making candle is chemically a mixture of – (1) aliphatic hydrocarbons (2) aromatic hydrocarbons (3) cyclic hydrocarbons (4) aliphatic and aromatic hydrocarbons

Last Answer : (1) aliphatic hydrocarbons Explanation: An aliphatic compound is a hydrocarbon compound containing carbon and hydrogen joined together in straight chains, branched trains or non-aromatic rings ... naturally occurring. Waxes are organic compounds that characteristically consist of long alkyl chains.

Description : Aliphatic hydrocarbons are mainly obtained from

Last Answer : petroleum.

Description : Name the homologous series of aliphatic hydrocarbons.

Last Answer : Aliphatic hydrocarbons have three homologous series – Alkanes, Alkenes and Alkynes

Description : How are aliphatic hydrocarbons classified?

Last Answer : Aliphatic hydrocarbons are classified into saturated and unsaturated hydrocarbons.