Latest questions in this category.
The s subshell, with its spherical shape, penetrates closest to the nucleus, experiencing less shielding and thus the greatest effective nuclear charge (Z_{eff).
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Trifluoroacetic acid is the most acidic due to the strong electron-withdrawing effect of fluorine atoms. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Given: What is the molality of a solution containing 10 g of sugar (molar mass = 342 g/mol) dissolved in 500 g of water? These values define the system as per NCERT data. Formula: Moles = 10 / 342 ≈ 0.0292 mol. This is standard NCERT relation. Substitution & Calculation: Molality = 0.0292 / 0.5 ≈ 0.0584 m. Result: The computed value matches expected outcome and confirms correct choice as per NCERT.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Given: The rate constant for a zero-order reaction is 1.5 × 10⁻²mol L^{-1 min^{-1 . What is the half-life if the initial concentration is 0.3 M? These values define the system as per NCERT data. Formula: For zero order, t_{1/2 = frac[R]_02k = frac0.32 × 1.5 × 10⁻²= 10 min .. This is standard NCERT relation. Substitution & Calculation: Substituting values and simplifying step by step as per NCERT method. Result: The computed value matches expected outcome and confirms correct choice as per NCERT.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Phosphorus pentachloride (PCl ₅ ) converts carboxylic acids to acid chlorides by replacing the hydroxyl group with chlorine. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Alkanes undergo free radical halogenation when treated with halogens in the presence of light. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Given: Which of the following lanthanoids has an ionic radius of 106 pm for its Ln^{3+ ion? These values define the system as per NCERT data. Formula: From the PDF, Cerium (Ce, Z = 58) has an ionic radius of 106 pm for Ce^{3+ .. This is standard NCERT relation. Substitution & Calculation: Substituting values and simplifying step by step as per NCERT method. Result: The computed value matches expected outcome and confirms correct choice as per NCERT.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Unlike cathode rays, the mass of canal rays (positive ions) varies with the gas in the tube, as they are ionized gas atoms. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
In 2H₂O₂ -> 2H₂O + O₂, only O (-1 to -2 and 0) changes; H (+1) stays constant. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Given: For the reaction N₂(g) + O₂(g) 2NO(g), K_c = 0.1 at 2000 K. If 0.5 mol of N₂ and 0.5 mol of O₂ are placed in a 5 L vessel, what is the equilibrium concentration of NO ? These values define the system as per NCERT data. Formula: Initial [N₂] = [O₂] = 0.5 / 5 = 0.1 M. This is standard NCERT relation. Substitution & Calculation: Let [NO] = 2x at equilibrium. Then, [N₂] = [O₂] = 0.1 - x . K_c = frac[NO]²[N₂][O₂] = (2x)²/(0.1 - x)² = 0.1 . 4x²/(0.1 - x)² = 0.1, 2x/0.1 - x = sqrt0.1 approx 0.316 . Solving: 2x = 0.0316 - 0.316x, 2.316x = 0.0316, x approx 0.0136, [NO] = 2x approx 0.027 M. Result: The computed value matches expected outcome and confirms correct choice as per NCERT.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Ethers with tertiary alkyl groups hydrolyze more easily due to carbocation formation. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
A phosphodiester bond links the 3’ -OH of one sugar to the 5’ phosphate of another in DNA and RNA, forming the backbone. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
