Learn

Friday, 9 October

JEE Main 2026 · ChemistryMultiple choiceSingle correctHardCalculation

JEE Main 2 April 2026, Shift 2, Chemistry Q52

Question 52 of 75 in this shift, Chemistry question 2 of 25, Section A.

The 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} respectively. 0.1 mol of H2A\mathrm{H_2A} was dissolved in 1L of 0.1 M HCl solution. The concentration of HA−\mathrm{HA^-} in the resultant solution is :
  1. (1)0.10.1 M
  2. (2)9.53×10−69.53 \times 10^{-6} M
  3. (3)8.1×10−88.1 \times 10^{-8} MOfficial answer
  4. (4)1.0×10−131.0 \times 10^{-13} M

Official answer

Option 3

NTA final key.

Chapter
Equilibrium
Topic
pH and Buffers
Idea tested
pH of Polyprotic Acids

Same idea in other shifts

Asked 2× in all
  1. 16 Mar 2021, Shift 2 · Q56Sulphurous acid (H2SO3\mathrm{H_2SO_3}) has Ka1=1.7×10−2K_{a_1}=1.7\times10^{-2} and Ka2=6.4×10−8K_{a_2}=6.4\times10^{-8}. The pH of 0.588 M H2SO3\mathrm{H_2SO_3}…MediumNumerical value

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 42 of the 174 JEE Main shifts held from 2017 to 2026.