NEET UG · Chemistry · Surface Chemistry

Surface Chemistry and Colloids: NEET previous year questions

This topic’s chapter, Surface Chemistry, is not in the NEET UG 2026 syllabus. It had 8 questions from 2017 to 2023; they are kept here for reference.

Asked in 10 years: 8; about 0.8 per paper
Years asked: 7/10; last asked 2023
Syllabus: Dropped; not in NEET UG 2026
Last asked: 2023; 3 papers ago

Key findings

01
Asked in 7 of 10 papers, 8 questions in all: #113 of 204 topics by ten-year total. Last asked in 2023.
02
71% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
03
The most repeated idea is Homogeneous and Heterogeneous Catalysis, asked 2 times (2017, 2023), usually as “identify example of catalysis type”.
04
NEET has asked 0 of the 6 ideas in this topic; 0 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (88%); 75% easy, 13% hard, and down from 1.1 to 0.0 questions a paper since 2024.

Questions per year

Up to 2023: 1.1; per paper
Since 2024: 0.0; -1.1
Usual gap: 1.0 yrs; between papers asking it
Swing: ±0.6; questions, year to year

How it is asked

Difficulty, format and skill

Across all 8 questions on Surface Chemistry and Colloids since 2017.

Difficulty

QUESTIONS

611

Easy6 · 75%
Medium1 · 13%
Hard1 · 13%

Format

One-line MCQ · 7 Q88%
Two statements · 1 Q13%

Skill tested

Recall · 5 Q63%
Concept · 2 Q25%
Application · 1 Q13%

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 0 of the 6 ideas in this topic. 0 have never been asked yet.

Asked directly0 · 0%
Touched inside another question6 · 100%
Never asked0 · 0%

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 · 25%25%2/10
- 2022 · Q59
  Given below are two statements : Statement I : In the coagulation of a negative sol, the flocculating power of the three given ions is in…
  mediumTwo statements
- 2018 · Q75
  On which of the following properties does the coagulating power of an ion depend ?
  easyOne-line MCQNew idea
Repeated2 · 25%25%2/10
1 · 13%13%1/10
1 · 13%13%1/10
1 · 13%13%1/10
1 · 13%13%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

6 different ideas were tested; 2 came more than once.

Homogeneous and Heterogeneous Catalysis2×
identify example of catalysis type
One-line MCQ · 4% next
Coagulation and the Hardy-Schulze Rule2×
property determining coagulating power
One-line MCQ · 4% next
Types of Colloids1×
classify example of colloid type
One-line MCQ · 4% next
Optical and Kinetic Properties of Colloids1×
identify example of a colloid property
One-line MCQ · 4% next
Electrical Double Layer and Zeta Potential1×
property determined by quantity
One-line MCQ · 4% next
Charge on Sols1×
identify mixture giving a charged sol
One-line MCQ · 4% next

Idea	Times	Format	Chance next	Foundation for
Homogeneous and Heterogeneous Catalysisidentify example of catalysis type	2	One-line MCQConcept	4%	–
Coagulation and the Hardy-Schulze Ruleproperty determining coagulating power	2	One-line MCQConcept	4%	–
Types of Colloidsclassify example of colloid type	1	One-line MCQRecall	4%	–
Optical and Kinetic Properties of Colloidsidentify example of a colloid property	1	One-line MCQRecall	4%	–
Electrical Double Layer and Zeta Potentialproperty determined by quantity	1	One-line MCQRecall	4%	–
Charge on Solsidentify mixture giving a charged sol	1	One-line MCQApplication	4%	–

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

Surface Chemistry and Colloids questions, year by year

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

NEET 20232 questions

Q66
Which one is an example of heterogenous catalysis?
Idea: Homogeneous and Heterogeneous Catalysis
EasyOne-line MCQ
Q96
Pumice stone is an example of -
Idea: Types of Colloids
New ideaEasyOne-line MCQ

NEET 20221 question

Q59
Given below are two statements : Statement I : In the coagulation of a negative sol, the flocculating power of the three given ions is in…
Idea: Coagulation and the Hardy-Schulze Rule
MediumTwo statements

NEET 20211 question

Q61
The right option for the statement “Tyndall effect is exhibited by”, is :
Idea: Optical and Kinetic Properties of Colloids
New ideaEasyOne-line MCQ

NEET 20201 question

Q128
Measuring Zeta potential is useful in determining which property of colloidal solution ?
Idea: Electrical Double Layer and Zeta Potential
New ideaEasyOne-line MCQ

NEET 20191 question

Q72
Which mixture of the solutions will lead to the formation of negatively charged colloidal $[AgI]I^-$ sol. ?
Idea: Charge on Sols
New ideaHardOne-line MCQ

NEET 20181 question

Q75
On which of the following properties does the coagulating power of an ion depend ?
Idea: Coagulation and the Hardy-Schulze Rule
New ideaEasyOne-line MCQ

NEET 20171 question

Q58
Which one of the following statements is not correct ?
Idea: Homogeneous and Heterogeneous Catalysis
EasyOne-line MCQ

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