Question

Assertion (A): The packing efficiency of simple cubic lattice is 52.4%. Reason (R): The number of atoms per unit cell is 2. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion:- \(H_2\)O is the only hydrides of the Chalcogens which is liquid. Reason :- In ice each O atom is surrounded by 4H-atom. a) Assertion and reason both are correct statements and reason is correct explanation for assertion. b) Assertion and reason both are correct statements but reason is not correct explanation for assertion. c) Assertion is correct statement but reason is wrong statement. d) Assertion is wrong statement but reason is correct statement.

Assertion: The packing efficiency is maximum for the fcc structure. Reason: The coordination number is 12 in fcc structures. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: 1 M glucose will have a higher boiling point than 2 M glucose. Reason: Elevation in boiling point is a colligative property which depends upon the number of particles of solute in the solution. A. If both Assertion and Reason are correct and reason is the correct explanation of Assertion . B. If both Assertion and Reason are correct and reason is not correct explanation of Assertion C. If Assertion is correct but Reason is incorrect. D. If Assertion is incorrect and Reason is correct.

Assertion (A): Most of the solids possess high melting point. Reason (R): They have strong intermolecular forces of attraction. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: o-Nitrophenol is less soluble in water than the m- and p-isomers. Reason: m- and p- Nitrophenols exist as associated molecules. (a) Both assertion and reason are true and the reason is the correct explanation of assertion. (b) Both assertion and reason are true but the reason is not the correct explanation of assertion. (c) Assertion is true but reason is false. (d) Assertion is false but reason is true.

Read the passage given below and answer the following questions: The polarity of carbon-halogen bond of alkyl halides is responsible for their Nucleophilic substitution, elimination and their reaction with metal atoms to form organ metallic compounds. Nucleophilic substitution reactions are categorized into SN1 and SN2 on the basis of their kinetic properties. Chirality has a profound role in understanding the reaction mechanisms of SN1 and SN2 reactions. SN2 reactions of chiral alkyl halides are characterized by the inversion of configuration while SN1 reactions are characterized by racemisation. ASSERTION -REASON TYPE A statement of assertion is followed by a statement of reason. Mark the correct choice from the options given below: (a) Both assertion and reason are true and reason is the correct explanation of assertion. (b) Both assertion and reason are true but reason is not the correct explanation of assertion. (c) Assertion is true but reason is false. (d) Assertion is false but reason is true. (i) Assertion : SN2 reactions do not proceed with retention of configuration. Reason : SN2 reactions proceed in a single step. (ii) Assertion : Tertiary alkyl halides show high reactivity in SN1 reaction. Reason : Tertiary carbocation has more stability. (iii) Assertion : Nucleophilic substitution reaction in an optically active alkyl halide gives a mixture of enantiomers. Reason : Reaction occurs by SN1 mechanism. (iv) Assertion : Primary allylic halides show higher reactivity in SN1 reactions than other primary alkyl halides. Reason : Intermediate carbocation is stabilized by resonance.