Assertion Reason Questions Chemistry Class 12 Chapter 11
Assertion Reason Questions Chemistry Class 12 Chapter 11
Assertion-Reason Questions In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choice.
(a) Assertion and reason both are correct statements but the reason is the correct explanation for assertion.
(b) Assertion and reason both are correct statements but the reason is not a correct explanation for assertion. مواقع تقبل باي بال لعبة كونكر
(c) Assertion is a correct statement but the reason is a wrong statement.
(d) Assertion is a wrong statement but the reason is correct
Q 1. Assertion: In Lucas test, 30 alcohols react immediately
Reason: An equimolar mixture of anhyd. ZnCl2 and conc. HCl is called Lucas reagent.
Ans 1. (b) Assertion and reason both are correct statements but the reason is not a correct explanation for assertion.
Q 2. Assertion: p-nitrophenol is more acidic than phenol
Reason: Nitro group helps in the stabilization of the phenoxide ion by dispersal of negative charge due to resonance.
Ans 2. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Q 3. Assertion: Bond angle in ethers is slightly less than the tetrahedral angle.
Reason: There are a repulsion between the two bulky (-R) groups.
Ans 3. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Q 4. Assertion: Phenol is more reactive than benzene towards electrophilic substitution reaction. Reason: In the case of phenol, the intermediate carbocation is more resonance stabilized.
Ans 4. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Phenol is more reactive than benzene towards electrophilic substitution reaction. The donation of the oxygen’s lone pair into the ring system increases the electron density around the ring. تعليم لعبة الطاولة That makes the ring much more reactive than it is in benzene. The intermediate carbocation is more resonance stabilized.
Assertion Reason Questions Chemistry Class 12 Chapter 11
Q 5. Assertion: Like bromination of benzene, bromination of phenol is also carried out in the presence of Lewis acid.
Reason: Lewis acid polarizes the bromine molecule.
Ans 5. (d) Assertion is the wrong statement but the reason is correct
Q 6. Assertion: o-Nitrophenol is less soluble in water than the m-and p-isomers
Reason: m and p-Nitrophenols exist as associated molecules.
Ans 6. (b) Assertion and reason both are correct statements but the reason is not a correct explanation for assertion.
Reason: Due to the presence of intramolecular hydrogen bonding, o-nitrophenol does not form hydrogen bonds with H2O but m and p-nitrophenol form hydrogen bonds with water.
Q 7. Assertion: Ethanol is a weaker acid than phenol.
Reason: Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH
Ans 7. (b) Assertion and reason both are correct statements but the reason is not a correct explanation for assertion.
Q 8. Assertion: Phenol on oxidation with KMnO4 gives meso-tartaric acid
Reason: Pure phenol is colourless but turns pink due to oxidation to phenoquinone.
Ans 8. (d) Assertion is the wrong statement but the reason is correct
Q 9. Assertion: Phenols give o- and p-nitrophenol on nitration with conc. HNO3 and H2SO4 mixture.
Reason: -OH group in phenol is o and p-directing
Ans 9. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Q 10. Assertion: Phenol is more reactive than benzene towards electrophilic substitution reaction.
Reason: In the case of phenol, the intermediate carbocation is more resonance stabilized.
Ans 10. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Q 11. Assertion: The boiling point of alcohol is higher than those of hydrocarbons of comparable molecular mass.
Reason: Alcohol show intramolecular hydrogen bonding.
Ans 11. (c) The assertion is a correct statement but the reason is the wrong statement.
Q 12. Assertion: Ethers behave as bases in the presence of mineral acids.
Reason: Due to the presence of lone pairs of electrons on oxygen.
Ans 12. (a) Assertion and reason both are correct statements but the reason is a correct explanation for assertion.
Due to the presence of lone pair of electrons on the oxygen atom, ethers behave as a base and form stable oxonium salts with mineral acids.
Assertion Reason Questions Chemistry Class 12 Chapter 11