NEET UG · Chemistry · Equilibrium

pH and Buffer Solutions: NEET previous year questions

13 questions in ten years of NEET, in 10 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 13; about 1.3 per paper
Years asked: 10/10; last asked 2026
Chance of a question next paper: 64%; historical rate, how we compute it
Weighted estimate: 1.1; model; history: 1.3 a paper on average, typically 1–2

Key findings

01
Asked in 10 of 10 papers, 13 questions in all: #50 of 204 topics by ten-year total.
02
92% of its questions since 2018 tested an idea never asked before; 1 repeated an idea from the year before.
03
The most repeated idea is Solubility Product from Solubility, asked 2 times (2017, 2018), usually as “numerical”.
04
NEET has asked 8 of the 91 ideas in this topic; 79 have never been asked, directly or indirectly.
05
Mostly asked as numerical (54%); 54% easy, 8% hard, and down from 1.4 to 1.0 questions a paper since 2024.

Questions per year

Up to 2023: 1.4; per paper
Since 2024: 1.0; -0.4
Usual gap: 1.0 yrs; between papers asking it
Swing: ±0.7; questions, year to year

How it is asked

Difficulty, format and skill

Across all 13 questions on pH and Buffer Solutions since 2017.

Difficulty

QUESTIONS

Easy7 · 54%
Medium5 · 38%
Hard1 · 8%

Format

Numerical · 7 Q54%
One-line MCQ · 5 Q38%
Other · 1 Q8%

Skill tested

Calculation · 8 Q62%
Concept · 2 Q15%
Recall · 2 Q15%
Application · 1 Q8%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 8 of the 91 ideas in this topic. 79 have never been asked yet.

Asked directly8 · 9%
Touched inside another question4 · 4%
Never asked79 · 87%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated2 · 15%15%2/10
- 2018 · Q77
  The solubility of $\mathrm{BaSO_4}$ in water is $2.42\times10^{-3}$ gL $^{-1}$ at 298 K. The value of its solubility product ( $K_{sp}$ )…
  easyNumericalAsked the year before
- 2017 · Q51
  Concentration of the $\mathrm{Ag^+}$ ions in a saturated solution of $\mathrm{Ag_2C_2O_4}$ is $2.2\times10^{-4}$ mol $\mathrm{L^{-1}}$ .…
  easyNumericalNew idea
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

12 different ideas were tested; 1 came more than once. pH of Salt Solutions is the foundation for 21 other ideas in the syllabus.

Solubility Product from Solubility2×
numerical
Numerical · 4% next
Solubility from Ksp1×
order/ranking of solubility from ksp
One-line MCQ · 6% next
pH of Polyprotic Acids1×
count correct statements on polyprotic acid
Other · 6% next · foundation for 3
pH of Salt Solutions1×
identify reagent to suppress a process
One-line MCQ · 6% next · foundation for 21
Lewis Acids and Bases1×
identify lewis acid among species
One-line MCQ · 4% next
Henderson-Hasselbalch Equation1×
numerical
Numerical · 4% next · foundation for 14
pH of Weak Acid-Weak Base Salt1×
numerical
Numerical · 4% next
Common-Ion Effect on Solubility1×
numerical
Numerical · 4% next
Conjugate Acid-Base Pair Ka and Kb Relationship1×
identify conjugate acid-base pair
One-line MCQ · 4% next
Identifying Buffer Solutions1×
identify buffer from mixtures
One-line MCQ · 4% next · foundation for 20
pH of Hydroxide Precipitation1×
numerical
Numerical · 4% next
pH of Acid-Base Neutralization Mixtures1×
numerical
Numerical · 4% next · foundation for 6

Idea	Times	Format	Chance next	Foundation for
Solubility Product from Solubilitynumerical	2	NumericalCalculation	4%	–
Solubility from Ksporder/ranking of solubility from ksp	1	One-line MCQCalculation	6%	–
pH of Polyprotic Acidscount correct statements on polyprotic acid	1	OtherConcept	6%	3 ideas
pH of Salt Solutionsidentify reagent to suppress a process	1	One-line MCQRecall	6%	21 ideas
Lewis Acids and Basesidentify lewis acid among species	1	One-line MCQRecall	4%	–
Henderson-Hasselbalch Equationnumerical	1	NumericalCalculation	4%	14 ideas
pH of Weak Acid-Weak Base Saltnumerical	1	NumericalCalculation	4%	–
Common-Ion Effect on Solubilitynumerical	1	NumericalCalculation	4%	–
Conjugate Acid-Base Pair Ka and Kb Relationshipidentify conjugate acid-base pair	1	One-line MCQConcept	4%	–
Identifying Buffer Solutionsidentify buffer from mixtures	1	One-line MCQApplication	4%	20 ideas
pH of Hydroxide Precipitationnumerical	1	NumericalCalculation	4%	–
pH of Acid-Base Neutralization Mixturesnumerical	1	NumericalCalculation	4%	6 ideas

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

pH and Buffer Solutions questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20261 question

Q52
The correct order of solubility of the given salts in water at 298 K is Salt | $K_{sp}$ at 298 K AgBr | $5.0\times10^{-13}$ …
Idea: Solubility from Ksp
New ideaHardOne-line MCQ · figure

NEET 20251 question

Q59
Phosphoric acid ionizes in three steps with their ionization constant values $K_{a_1}$ , $K_{a_2}$ and $K_{a_3}$ , respectively, while K is…
Idea: pH of Polyprotic Acids
New ideaMediumOther

NEET 20241 question

Q93
During the preparation of Mohr's salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of…
Idea: pH of Salt Solutions
New ideaEasyOne-line MCQ

NEET 20231 question

Q83
Amongst the given options which of the following molecules / ion acts as a Lewis acid?
Idea: Lewis Acids and Bases
New ideaEasyOne-line MCQ

NEET 20221 question

Q56
The pH of the solution containing 50 mL each of 0.10 M sodium acetate and 0.01 M acetic acid is [Given p $K_a$ of $\mathrm{CH_3COOH}$ = 4.57]
Idea: Henderson-Hasselbalch Equation
New ideaEasyNumerical

NEET 20211 question

Q54
The $\mathrm{pK_b}$ of dimethylamine and $\mathrm{pK_a}$ of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for…
Idea: pH of Weak Acid-Weak Base Salt
New ideaEasyNumerical

NEET 20201 question

Q92
Find out the solubility of $\mathrm{Ni(OH)_2}$ in 0.1 M NaOH. Given that the ionic product of $\mathrm{Ni(OH)_2}$ is $2\times10^{-15}$ .
Idea: Common-Ion Effect on Solubility
New ideaMediumNumerical

NEET 20193 questions

Q62
pH of a saturated solution of $Ca(OH)_2$ is 9. The solubility product $(K_{sp})$ of $Ca(OH)_2$ is :
Idea: pH of Hydroxide Precipitation
New ideaMediumNumerical
Q71
Conjugate base for Brönsted acids $H_2O$ and HF are :
Idea: Conjugate Acid-Base Pair Ka and Kb Relationship
New ideaEasyOne-line MCQ
Q77
Which will make basic buffer ?
Idea: Identifying Buffer Solutions
New ideaMediumOne-line MCQ

NEET 20182 questions

Q74
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations : a. 60 mL $\frac{M}{10}$ HCl +…
Idea: pH of Acid-Base Neutralization Mixtures
New ideaMediumNumerical
Q77
The solubility of $\mathrm{BaSO_4}$ in water is $2.42\times10^{-3}$ gL $^{-1}$ at 298 K. The value of its solubility product ( $K_{sp}$ )…
Idea: Solubility Product from Solubility
Asked last yearEasyNumerical

NEET 20171 question

Q51
Concentration of the $\mathrm{Ag^+}$ ions in a saturated solution of $\mathrm{Ag_2C_2O_4}$ is $2.2\times10^{-4}$ mol $\mathrm{L^{-1}}$ .…
Idea: Solubility Product from Solubility
EasyNumerical

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.