JEE Main Chemistry · Equilibrium

pH and Buffers in JEE Main

Name: pH and Buffers: JEE Main previous year questions
Creator: Lumi

pH and Buffers (Chemistry, Equilibrium) came 17 times in 16 of the 42 JEE Main shifts Lumi analysed, across 13 distinct ideas. 10 of them came in 2024–26; it was last asked in 2026.

Questions: 17; in 16 shifts
Ideas asked: 13; 4 asked more than once
Numerical answer: 9; 53% of its questions
Pattern: Asked most years; last asked 2026

Questions each year

In the shifts Lumi analysed for each year.

Difficulty and format

Easy 6Medium 9Hard 2

Format

Numerical value9 Q
Single correct7 Q
Other1 Q

Ideas inside the topic

13 ideas

Acidic Buffer pH Calculation2 Q
pH of Polyprotic Acids2 Q
pH of Strong Acids and Bases2 Q
pH of Weak Acids and Bases2 Q
pH Change on Adding Strong Acid/Base to Buffer1 Q
Basic Buffer pH Calculation1 Q
Buffer Formation via Partial Neutralization1 Q
Buffer Formation via Partial Neutralization1 Q
Volume Ratios for Buffer Preparation1 Q
pH of Strong Acid and Strong Base Mixtures1 Q
pH of Salt Solutions1 Q
pH of Weak Acid-Weak Base Salts1 Q

Where it sits

Part of Equilibrium, which had 52 questions in all. pH and Buffers accounts for 33% of them. In Lumi's JEE taxonomy it belongs to Physical Chemistry.

Some questions sit in other chapters too: Solutions.

Every question

All 17 pH and Buffers questions

Newest first, each with its options and official answer.

2 Apr 2026, Shift 2 · Q52The first and second ionization constants of a weak dibasic acid $\mathrm{H_2A}$ are $8.1 \times 10^{-8}$ and $1.0 \times 10^{-13}$ …HardSingle correct
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
4 Apr 2026, Shift 1 · Q74The pH of a solution obtained by mixing $5$ mL of $0.1$ M $\mathrm{NH_4OH}$ solution with $250$ mL of $0.1$ M $\mathrm{NH_4Cl}$ solution…MediumNumerical value
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 Apr 2026, Shift 1 · Q56Arrange the following resultant mixtures in increasing order of their pH values A. 10 mL 0.2 M $\mathrm{Ca(OH)_2}$ + 25 mL 0.1 M HCl B. 10…MediumOther
6 Apr 2026, Shift 2 · Q56Given is a concentrated solution of a weak electrolyte $\mathrm{A_xB_y}$ of concentration 'c' and dissociation constant 'K'. The degree of…HardSingle correct
4 Apr 2025, Shift 2 · Q71x mg of $\mathrm{Mg(OH)_2}$ (molar mass = 58) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of…EasyNumerical value
7 Apr 2025, Shift 1 · Q54An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution…EasySingle correct
7 Apr 2025, Shift 2 · Q72One litre buffer solution was prepared by adding 0.10 mol each of $\mathrm{NH_3}$ and $\mathrm{NH_4Cl}$ in deionised water. The change in…MediumNumerical value
30 Jan 2024, Shift 2 · Q83The pH of an aqueous solution containing 1M benzoic acid ( $\mathrm{pK_a} = 4.20$ ) and 1M sodium benzoate is 4.5. The volume of benzoic…MediumNumerical value
13 Apr 2023, Shift 2 · Q8520 mL of 0.1 M NaOH is added to 50 mL of 0.1 M acetic acid solution. The pH of the resulting solution is ______ $\times10^{-2}$ (Nearest…MediumNumerical value
25 Jul 2022, Shift 1 · Q64 $20$ mL of $0.1$ M $\mathrm{NH_4OH}$ is mixed with $40$ mL of $0.05$ M HCl. The pH of the mixture is nearest to : (Given :…MediumSingle correct
28 Jul 2022, Shift 1 · Q85 $K_a$ for butyric acid ( $\mathrm{C_3H_7COOH}$ ) is $2\times10^{-5}$ . The pH of 0.2 M solution of butyric acid is __________…EasyNumerical value
3 Aug 2021, Shift 2 · Q55The pH of the solution resulted when 150 mL of 0.1 M ammonia solution is titrated with 50 mL of 0.1M HCl [ $\mathrm{pK_b(NH_3)}$ = 4.7] is…MediumNumerical value
16 Mar 2021, Shift 2 · Q56Sulphurous acid ( $\mathrm{H_2SO_3}$ ) has $K_{a_1}=1.7\times10^{-2}$ and $K_{a_2}=6.4\times10^{-8}$ . The pH of 0.588 M $\mathrm{H_2SO_3}$ …MediumNumerical value
18 Mar 2021, Shift 1 · Q55In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the…EasyNumerical value
2 Apr 2017 (offline) · Q40 $pK_a$ of a weak acid (HA) and $pK_b$ of a weak base (BOH) are 3.2 and 3.4, respectively. The pH of their salt (AB) solution is :EasySingle correct