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JEE Main Chemistry Solutions 2026 JEE Main 2026 (08 April Shift 2)

JEE Main Chemistry Question (2026) — Solution

Question

Which of the following statements are not correct? A. For water, magnitude of K_b is more than the magnitude of K_f. B. The elevation in boiling point of water when a non-volatile solute is added to it is larger in magnitude than its depression in freezing point. C. Osmotic pressure measurement is preferred over any other colligative property to determine molar mass of proteins and polymers. D. The dimerised form of benzoic acid in benzene is C_6H_5- O O \| C-OH O= OH | C -C_6H_5 Choose the correct answer from the options given below:

Options

  1. A. A and B only
  2. B. A and D only
  3. C. A, B and D only
  4. D. A, C and D only

Answer

C. A, B and D only

Step-by-step solution

For water, the molal elevation constant K_b = 0.52 K kg mol ^ -1 and the molal depression constant K_f = 1.86 K kg mol ^ -1 . Thus, K_b For a solution with a given molality m of a non-volatile solute, the elevation in boiling point is T_b = K_b m and the depression in freezing point is T_f = K_f m. Since K_b Osmotic pressure measurement is preferred for determining the molar mass of macromolecules such as proteins and polymers because the measurement is done at room temperature and the magnitude of osmotic pressure is significant even for very dilute solutions. Statement C is correct. In benzene, benzoic acid undergoes dimerization through intermolecular hydrogen bonding, forming a cyclic dimer with two hydrogen bonds. The structure given in statement D represents a linear association with only one hydrogen bond. Statement D is incorrect. Therefore, statements A, B, and D are incorrect. Answer: A, B and D only

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