CHEMISTRY

CHEMISTRY

What is the major product of Friedel-Crafts alkylation of anisole with ethyl chloride?

The ethyl group gets attached at the ortho and para positions due to the +M effect of the -OCH ₃ group. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

What is the maximum number of hydrogen bonds that one molecule of CH₃NH₂ can form with water?

Methylamine ( CH₃NH₂ ) has two N-H bonds (each donating one H-bond) and one lone pair (accepting one H-bond), allowing a maximum of three hydrogen bonds with water.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII), Chapter: Chemical Bonding (Latest NCERT 2026-27), Topic: Hybridization of nitrogen in CH₃NH₂, sp³ hybridization and pyramidal geometry

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CHEMISTRY

How many grams of NH₃ are produced from 7 g of N₂ in the reaction N₂ + 3H₂ -> 2NH₃ with excess H₂? (Atomic masses: N = 1

Given: How many grams of NH₃ are produced from 7 g of N₂ in the reaction N₂ + 3H₂ -> 2NH₃ with excess H₂? (Atomic masses: N = 14, H = 1) Formula: Moles of N₂ = 7 / 28 = 0.25 mol. Substitution & Calculation: 1 mol N₂ produces 2 mol NH₃. Moles of NH₃ = 0.25 × 2 = 0.5 mol. Molar mass of NH₃ = 17 g/mol. Mass = 0.5 × 17 = 8.5 g. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

The deficiency of which vitamin causes scurvy?

Vitamin C (ascorbic acid) deficiency leads to scurvy, characterized by bleeding gums, due to its role in collagen synthesis. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

Which molecule has a ntral atom with an expanded octet exceeding eight electrons?

In PF₅, phosphorus has 10 electrons around it (5 bonds), exceeding the octet due to available 3d orbitals. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

How many grams of O₂ are required to react with 14 g of N₂ to form N₂O₅? (Atomic masses: N = 14, O = 16)

Given: How many grams of O₂ are required to react with 14 g of N₂ to form N₂O₅? (Atomic masses: N = 14, O = 16) Formula: Moles of N₂ = 14 / 28 = 0.5 mol. Substitution & Calculation: Reaction: 2N₂ + 5O₂ -> 2N₂O₅ . . 2 mol N₂ require 5 mol O₂. Moles of O₂ = (5 / 2) × 0.5 = 1.25 mol. Mass = 1.25 × 32 = 40 g. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

For an exothermic reaction at constant pressure, what is the relationship between Δ H and Δ U?

For an exothermic reaction, Δ H < 0. If Δ n_g < 0 (fewer gas moles in products), Δ H < Δ U because Δ H = Δ U + Δ n_g RT and Δ n_g RT < 0. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

Calculate the wavelength of radiation with a frequency of 4.0 × __10POW₁₄__Hz. (c = 3.0 × __10POW₈__m s^{-1)

Given: Calculate the wavelength of radiation with a frequency of 4.0 × __10POW₁₄__Hz. (c = 3.0 × __10POW₈__m s^{-1) Formula: Wavelength lambda = c/nu = frac3.0 × __10POW₈₄__.0 × __10POW₁₄__= 7.5 × 10⁻⁷m = 750 nm.. Substitution: Substituting given values into formula as per NCERT 2026-27 method. Calculation: Simplifying step by step with proper SI units like m/s², J kg⁻¹ K⁻¹, 10⁻⁵, A m⁻¹ etc. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

What is the mass percentage of a solution formed by mixing 120 g of a 20% (w/w) solution with 180 g of a 10% (w/w) solut

Given: What is the mass percentage of a solution formed by mixing 120 g of a 20% (w/w) solution with 180 g of a 10% (w/w) solution? Formula: Mass of solute from first = 0.20 × 120 = 24 g. Substitution & Calculation: Mass of solute from second = 0.10 × 180 = 18 g . Total solute = 24 + 18 = 42 g. Total mass = 120 + 180 = 300 g. Mass % = 42/300 × 100 = 14% . Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

A reaction has the rate law Rate = k[A][B]⁰ . If [A] is increased by a factor of 4, what happens to the rate?

Given: A reaction has the rate law Rate = k[A][B]⁰ . If [A] is increased by a factor of 4, what happens to the rate? Formula: Rate = k[A], new rate = k(4[A]) = 4k[A]. Substitution & Calculation: Rate increases by a factor of 4. Final Result: The computed value matches expected outcome and confirms correct choice as per latest NCERT 2026-27.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

Which of the following does not undergo Aldol condensation?

Benzaldehyde does not undergo Aldol condensation because it lacks α-hydrogen atoms. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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CHEMISTRY

Which complex shows ionization isomerism with [Co(NH₃)5NO₂]Cl₂ ?

[Co(NH₃)5Cl]NO₂Cl swaps Cl^- and NO₂^- with [Co(NH₃)5NO₂]Cl₂, exhibiting ionization isomerism. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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