JEE Main: Did These Questions Have Wrong Answers In JEE Main Answer Key?

JEE Main: Did These Questions Have Wrong Answers In JEE Main Answer Key?

Edited By Tavneet Bedi | Updated on May 05, 2022 08:57 AM IST | #JEE Main

The Joint Entrance Examination (JEE) Main is conducted by the National Testing Agency (NTA), and every year, lakhs of students appear for the exam. It is the entrance test – or the preliminary selection round – for the top engineering colleges in the country including the Indian Institutes of Technology (IIT), National Institutes of Technology (NIT), Indian Institutes of Information Technology (IIIT) and many more government institutions.

Clearly, JEE Main is critical. However, JEE Main 2021 had questions which were conceptually or factually ambiguous and some of them were simply incorrect, going by the JEE Main answer key. Last year, the exam was conducted in four phases – February, March, July and August – across 26 Shifts. The result was declared in September.

Here, Careers360 looks into the questions asked in the July and August shifts, and highlights some of the errors in the JEE Main previous year question paper’s Chemistry section. The necessary changes required for these questions were absent from the NTA JEE Main answer keys, which could have affected the scorecards of many candidates in the JEE Main result.

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These questions, along with their respective problems, are listed out below:

JEE Main 2021: Attempt 3

July 20, Shift 1

Question ID : 86435117255

JEE Main Answer Key: 172

1651642594093


The issue:

The unit in which Kp is to be reported has not been specified in the question.

So, a student solving for the unit as (Pa)-1 will get an answer of 0.172 which would be rounded off to 0 while the given answer will be in units of (kPa)-1

1651642593666

____________________________________________________________________________

July 20, Shift 2

Question ID : 86435117528

JEE Main Answer Key: 1

1651642594816


The issue:

There is a conceptual error in the question. A negatively-charged sol cannot be precipitated by a negatively-charged ion.

Also, the coagulating value is defined as the minimum concentration of an electrolyte in millimoles per litre required to cause precipitation of a sol in two hours.

So, there arises another problem: How do you extrapolate data for two hours from the one-hour data?

____________________________________________________________________________

July 22, Shift 2

Question ID : 86435117785

JEE Main Answer Key: 86435159952 (Option 2)

1651642595012


Question and Option IDs

1651642592072

The issue:

Multiple options given in the question (Options 1,2 and 3) are capable of forming tertiary alcohol on reaction with excess of Grignard reagent (CH3MgBr) followed by hydrolysis.

Option 1: Alpha- Beta unsaturated carbonyl compounds show direct addition to the carbonyl group with Grignard reagent. Hence, tertiary alcohols will be obtained from the carbonyl groups

Option 3: Grignard reagent can add to a ketone, forming a tertiary alcohol.

____________________________________________________________________________

July 25, Shift 1

Question ID : 86435118234

JEE Main Answer Key: 86435161299 (Option 1)


1651642595826

The issue:

Lewis acids are not used with Phenol because Phenol itself forms a complex with the Lewis acid, due to which the ring becomes deactivated towards Electrophilic Substitution.

In fact, this reaction of Phenol with a Lewis acid FeCl3 is actually used to detect the presence of Phenol in solution. Phenol forms a complex with neutral FeCl3 and produces a violet colour.

Correct answer should be 86435161298 [Option (3)]

____________________________________________________________________________

July 25, Shift 1

Question ID : 86435118225

JEE Main Answer Key: 86435161264 (Option 3)

1651642595404


The issue:

Be is not an alkaline earth metal as its oxide and hydroxide are Amphoteric in nature.

Here is an excerpt from NCERT textbook’s chapter on the s Block elements confirming it.

1651642595160

Hence, Statement I is also correct in the given question.

Correct answer should be 86435161261 [Option (2)]

____________________________________________________________________________

July 27, Shift 1

Question ID : 86435118870

JEE Main Answer Key: 5

1651642594267


The issue:

Data given is insufficient to solve the problem.

Molality (m) can be calculated from the density of solution only when the Molarity (M) is also given in the question.

In the question, Molarity has not been provided and thus the question cannot be solved.

____________________________________________________________________________

July 27, Shift 2

Question ID : 86435119236

JEE Main Answer Key: 300

1651642596272

The issue :

The answer in the JEE Main final answer key was wrong. The answer should have been 600.

1651642592994

____________________________________________________________________________

JEE Main 2021: Attempt 4

August 26, Shift 2

Question ID : 86435120226

JEE Main Answer Key: 50

1651642596053


The issue :

The answer given in the answer key is wrong. The answer should be 0.

1651642592640

The answer is 0.02 which would be rounded off to 0.

For the answer to be 50, the value of (Kc)-1 had to be asked.

____________________________________________________________________________

August 27, Shift 1

Question ID : 86435120586

JEE Main Answer Key: 4

1651642593388

The issue :

The answer given is 4 because the inner 4f electrons have not been counted.

The question does not say that we need to consider only the 5f electrons

____________________________________________________________________________

August 31, Shift 2

Question ID : 86435121290

JEE Main Answer Key: 86435170463 (Option 4)

1651642595606

1651642591877

The issue :

Alcoholic NaOH causes dehydrohalogenation (elimination) and not substitution.

The answer should be 86435170462 (Option 2)

____________________________________________________________________________

August 31, Shift 2

Question ID : 86435121287

JEE Main Answer Key: 86435170452 (Option 2)

1651642594461

The issue :

None of the options is correct.

All the given options contain permanganate ion (MnO4-) which contains Mn in its highest oxidation state (+7) and hence, it cannot show disproportionation reaction

Question should have been awarded as bonus

____________________________________________________________________________

September 1, Shift 2

Question ID : 86435121562

JEE Main Answer Key: 86435171281 (Option 4)

1651642594652

1651642591663

The issue :

Options 1 and 4 can both be correct but only Option 4 has been given as the correct answer.

Acenaphthene (compound in Option 1) is also Aromatic in nature.

____________________________________________________________________________

Apart from the above-mentioned questions, there were also some in the integer section that had very lengthy mathematical calculations and whose answers had to be rounded off to the nearest integers.

These questions are usually solved by approximations and it is very difficult for students to arrive at the correct integer answer. Previously, these questions had a correct range for the answer, which gave students some leeway to make appropriate approximations in calculations.

Now, with negative marking in the numerical response questions, this becomes an even bigger problem. Considering the high-stakes nature of the JEE Mains, even a few such errors can have significant ramifications for applicants and be deeply demoralising.

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Questions related to JEE Main

Have a question related to JEE Main ?

Hello,

For downloading JEE Main 2025 sample papers, you can access them from various educational resources that provide free or structured content:

Careers360 lists sample and past JEE papers with solutions available for download, which can be very useful for targeted preparation.

To download sample papers with solution, visit : https://engineering.careers360.com/articles/jee-main-sample-papers

Hope it helps !

Hello,

To view the available books and study materials for specific exams like JEE Main or JEE Advanced on Careers360, follow these steps:

  1. Navigate to the Careers360 Website : Visit Careers360 and use their search function to locate resources for JEE Main, JEE Advanced, or other exams.

  2. Explore the Study Material Section : Careers360 provides detailed lists of e-books, sample papers, and study guides. For instance, for JEE Main, you can find:

    • Exam preparation books including solved question papers and guides for Physics, Chemistry, and Mathematics.
    • Specialized materials like formula sheets, mock tests, and previous years' papers.
  3. Filters and Categories : Use filters on the site to narrow down books by type (e.g., question papers, study guides), education level, or specific topics relevant to JEE Main or JEE Advanced.

  4. Free and Paid Options : Careers360 offers both free downloads and premium study packages. The "JEE Main Knockout Programme," for example, includes comprehensive resources such as video lectures and expert guidance.

For quick access, you can directly search for study material for a given exam on the Careers360 site, ensuring you stay updated with the latest editions and resources.

To get study material, visit :

1. https://engineering.careers360.com/articles/best-books-for-jee-main

2. https://engineering.careers360.com/download/jee-main-ebooks

Hope it helps !

hello,


To start JEE Main preparation, allocate 6–8 hours daily. Focus on Physics, Chemistry, and Maths equally. Study in blocks of 2 hours with breaks. Morning: Revise concepts and solve NCERT questions. Afternoon: Practice numericals and past papers. Evening: Attempt mock tests or solve advanced problems. Dedicate Sundays to full-length mock tests and analysis. Ensure 7 hours of sleep and daily exercise. Adjust based on your school/college timings.

You can check out the link below for a detailed schedule

https://engineering.careers360.com/articles/how-prepare-for-jee-main-in-6-months

Hello Aastha,

Yes, it's okay to use your mother's name as per the Aadhaar card, "Mamta Walia," while filling out the JEE application form. However, during document verification or counseling, there could be a discrepancy between the 10th marksheet and Aadhaar card. To avoid future issues, keep an affidavit or a notarized document ready explaining the name difference, or get it corrected in either document if possible.

For more details, you can check out an article by Careers360 whose link is given below:

Link: https://engineering.careers360.com/articles/how-to-fill-jee-main-application-form


I hope this answer helps you. If you have more queries then feel free to share your questions with us we will be happy to assist you.

Thank you and wishing you all the best for your bright future.



Hello aspirant,

According to the most recent NTA announcement about the JEE Main 2025 application form correction feature, candidates will not be able to change their uploaded photo if it was originally submitted incorrectly.

So you can change your photo in JEE MAINS correction window.

Thank you

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