GATE 2021 Chemical (CH) Answer Key (Available) – Check Question Paper and Solutions

GATE 2021 Chemical Engineering (CH) Answer Key can be checked from this page. IIT Bombay conducted GATE 2021 Chemical Engineering paper on February 13, 2021, from 09:30 Am to 12:30 PM. Candidates can use the answer key to cross-check their answers and calculate their probable score. Moreover, IIT Bombay release GATE Chemical Engineering Answer key 2021 online at To download it, you will need to enter your enrollment number and date of birth. To check the GATE 2021 Chemical Engineering (CH) answer key, read below.

Latest: GATE 2021 CH answer key available. Check questions & answers from below.

GATE 2021 Chemical Engineering (CH) Answer Key

  • Exam Date – February 13, 2021
  • Subject paper – Chemical Engineering (CH)
  • Time – 09.30 am to 12.30 pm
  • GATE 2021 Result Date: 22 March 2021

If you appeared for GATE 2021 CH paper, then submit your questions and we will provide you the answer key. Click on the button below to submit answers. All the best!

Q1. In a batch doing experiment a solid with a critical moisture content of 0.2kg water / kg dry solid is dried from an initial moisture content of 0.35 kg water / dry solid to a final moisture content of 0.1 kg water/ kg dry solid in 5 hours. In the constant rate regime, the rate of drying is 2 kg water / kg dry air. The entire falling regime is assumed to be zero. The mass of dry solid per unit area is ____ kg/ m2.
Ans. 35

Q2. A distillation column handling a binary mixture of A and B operating at total reflex. It has two ideal stages including the reboiler. The mole function of the more volatile component in the residue is 0.1. The average relative volatility αAB is 4. The model fraction of A in the distillate is
Ans. 0.64

Q3. A binary liquid mixture consists of two pieces 1 and 2, let 𝛄 and x represent the activity coefficient. using a molar excess Gibbs free energy model ln 𝛄1 vs x1 and ln 𝛄2 vs x1 are plotted. A tangent drawn to the ln 𝛄1 vs x1 curve at a mole fraction of x1 = 0.2 ha slope = 1.728. The slope of the tangent drawn to the ln 𝛄1 vs x1 curve at the same mole fraction ________?
Ans. 0.432

Q4. A gaseous mixture of 1 bar and 300K consists of 20 mol% CO2 and 80 mole% insert gas. Assume the gas to be real. R = 8.314 J/mol.K. The magnitude of minimum work done required to separate 100 mol of this mixture at 1 bar and 300K into pure CO2 and the insert gas at the same temp and pressure is ____ kJ.
Ans. 125

Q5. A process has a transfer function G(s) = Y(s) / X(s) = 20 / 900000s2 + 240s + 1. Initally the process is at a steady state with x(t=0) = 0.4 and y(t=0) = 100. If a step charge in x is given from 0.4 to 0.5. The maximum value of y that will be observed before it reaches the new steady state is ____.
Ans. 0.254

Q6. The inherent characteristics of three control values P, Q and R. The correct option is/are –
A. P is an equal % valve
B. Q is quick opening valve
C. P is quick opening valve
D. R is an equal % valve
Ans. Options C and D are correct.

Q7. In a solvent regeneration process, a gas is used to strip a solute from the liquid in counter-current packed bed tower operating under isothermal condition pure gas is used in this striping operation. All solution is diluted and Henry’s law is applicable here y mole fraction of solute in the gas phase in equilibrium with the liquid phase of solute mole fraction x, and M is the Henry Law constant. Let x1 be the mole fraction of the solute in the leaving liquid, and x2 be the mole fraction of the solute in entering liquid when the value of the ratio of the liquid to gas molar flow rate is equal to M, the overall NTOI is given by –
Ans. x2 – x1 / x1

You can also check: GATE answer keys for all 27 papers

GATE 2021 Chemical Engineering (CH) Answer Key Dates

You can get the official GATE answer key 2021 within 10 days of the GATE 2021 exam if the trend from last year is followed. However, the schedule of GATE 2021 given by IIT Bombay is as follows:

GATE 2021 Answer KeyDates
GATE 2021 exam dates06, 07, 13, 14 Feb 2021
GATE 2021 answer keyto be announced
GATE result declaration22 Mar 2021
Last date to download scorecard31 May 2021

How to Calculate Score Using GATE 2021 CH Answer Key?

You can calculate GATE 2021 estimated score using the marking scheme of the exam which is as follows:

Step 1: You have to first download the GATE 2021 answer key for your subject paper.

Step 2: Also, download the GATE 2021 response sheet and question paper of GATE 2021. IIT releases the question paper and response sheet too on the official website

Step 3: Now, match the responses given in the answer from the response mentioned in the response sheet.

Step 4: Next, the candidates need to add or deduct marks, as per the marking scheme. It is as follows:

Type of questionsNegative Marking
MCQs– 1/3rd Mark will be deducted for 1 mark question
– 2/3rd Mark will be deducted for 2 marks question
MSQs– 1/3rd Mark will be deducted for 1 mark question
– 2/3rd Mark will be deducted for 2 marks question
NATsNo negative marking

Step 5: Finally using the marking scheme, candidates can get their estimated score of GATE.

GATE Chemical Engineering (CH) Paper Cut Off

You can check the cutoff of GATE 2021, with the result of GATE. Till then, we have given below the GATE 2021 cutoff for IN paper for the last few year:

YearGATE CH paper cutoff
GATE CH paper cutoff
GATE CH paper cutoff
(SC / ST / PwD)

GATE 2021 Question Paper

GATE 2021 question papers are available officially after the exam on the website of GATE. It is actually uploaded with the answer key of GATE 2021 in PDF format. The question paper has all the questions asked in GATE 2021. Candidates can check the question papers available subject wise for all 27 papers of GATE 2021. Thus, using the GATE question paper, answer key, and response sheet candidates can evaluate their score in the exam.

Official GATE 2021 CH Answer Key

The official GATE answer key is of two types: Provisional answer key and Final answer key. IITs release the provisional answer key after the exam. It is open for a challenge by the candidates. As per all the valid challenges, IIT makes changes in the answer key. The updated answer key is the final answer key. A further challenge is not possible in the final answer key. Also, as per the answers in the final answer key, result of GATE is evaluated.

How to Download GATE 2021 Official Answer Key

Here is how you can download GATE 2021 official answer key:

  • 1st step: Go to, there is no need to login at GOAPS.
  • 2nd step: Next, locate the link for answer key of GATE 2021.
  • 3rd step: Then, locate the subject paper for which you appeared in GATE 2021.
  • 4th step: After that, click on the answer key link corresponding to your subject paper name.
  • 5th step: The answer key is downloaded in your system as PDF file.
  • 6th step: Use the same to evaluate a probable score in the exam.

GATE 2021 Result

Based on the final answer key, IITs prepare GATE 2021 result. Candidates can check result by logging in with enrollment ID and password at GOAPS. Those who obtain cut-off marks qualify in GATE 2021. Cut off depends on the performance of test-takers. On basis of the result, candidates can participate in CCMT 2021, which is the GATE counselling. Or they can seek PSU recruitment.

 The candidates have to keep a printout of their scorecards for future procedures of admissions and / or recruitment. The GATE Scorecard is valid for a period of 3 years.

GATE 2021

The Graduate Aptitude Test in Engineering (GATE) 2021 is a national level entrance exam. The score of GATE 2021 is used for admission in institutes like IITs, NITs, IIITs and other GFTIs for admission in M.Tech and research courses. Furthermore, PSUs also use GATE score for recruitment. This year 2 new subject papers are included in the exam, they are ES (Environmental Science and Engineering) and XH (Humanities and Social Sciences). There are 3 types of questions in the exam such as multiple-choice questions, multiple-selective questions, and numerical answer type questions. 

GATE 2021 Chemical Engineering (CH) Answer Key FAQs

How do I download the GATE answer key?

When the official answer key releases, candidates will have to visit the official GATE 2021 website,, and download the answer key PDF.

 Is there any difference between the Official and the Unofficial GATE Answer Key?

Yes, official and Unofficial Answer Key are different. At times, the coaching institutes that publish the Unofficial versions of the Answer Key may not know the complete question or there might be certain discrepancy due to ambiguous questions, the answers may differ. However, the candidates must note that only the Official Answer Key is used for evaluating GATE results.

When will IIT release GATE 2021 answer key?

The memory based answer keys releases on the day of the exam. However, the official answer key releases within 10 days of the last GATE exam.

Official website:

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