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Saturday, 31 October

JEE Main 2023 · ChemistryMultiple choiceOtherMediumConceptual

JEE Main 15 April 2023, Shift 1, Chemistry Q64

Question 64 of 90 in this shift, Chemistry question 4 of 30, Section A.

Which of the following statement(s) is/are correct? (A) The pH of 1×10−81 \times 10^{-8} M HCl solution is 8. (B) The conjugate base of H2PO4−\mathrm{H_2PO_4^-} is HPO42−\mathrm{HPO_4^{2-}}. (C) KwK_w increases with increase in temperature. (D) When a solution of a weak monoprotic acid is titrated against a strong base at half neutralisation point, pH=12pKa\mathrm{pH} = \frac{1}{2}\mathrm{p}K_a. Choose the correct answer from the options given below:
  1. (1)(A), (B), (C)
  2. (2)(B), (C), (D)
  3. (3)(B), (C)Official answer
  4. (4)(A), (D)

Official answer

Option 3

NTA final key.

Chapter
Equilibrium
Topic
pH and Buffers
Idea tested
pH of Extremely Dilute Strong Acids/Bases

Same topic in other shifts

All pH and Buffers questions
  1. 2 Apr 2026, Shift 2 · Q52The first and second ionization constants of a weak dibasic acid H2A\mathrm{H_2A} are 8.1×10−88.1 \times 10^{-8} and 1.0×10−131.0 \times 10^{-13}…HardSingle correct
  2. 2 Apr 2026, Shift 2 · Q56At 25°C, 20.0 mL of 0.2 M weak monoprotic acid HX is titrated against 0.2 M NaOH. The pH of the solution (a) at the start of the titration…MediumSingle correct
  3. 4 Apr 2026, Shift 1 · Q74The pH of a solution obtained by mixing 55 mL of 0.10.1 M NH4OH\mathrm{NH_4OH} solution with 250250 mL of 0.10.1 M NH4Cl\mathrm{NH_4Cl} solution…MediumNumerical value
  4. 4 Apr 2026, Shift 2 · Q5520 mL of a solution of acetic acid required 28.4 mL of 0.1 M NaOH for its neutralization. A solution (X) was prepared by mixing 20 mL of…EasySingle correct
  5. 5 Apr 2026, Shift 1 · Q56Arrange the following resultant mixtures in increasing order of their pH values A. 10 mL 0.2 M Ca(OH)2\mathrm{Ca(OH)_2} + 25 mL 0.1 M HCl B. 10…MediumOther
  6. 6 Apr 2026, Shift 2 · Q56Given is a concentrated solution of a weak electrolyte AxBy\mathrm{A_xB_y} of concentration 'c' and dissociation constant 'K'. The degree of…HardSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.