MCH 019 Solved Guess Paper from Unnati Educations gives you twenty exam-style questions on Green Chemistry with the full written answer under each one. It is built for learners sitting the December 2026 Term-End Examination of Master of Science (Chemistry) and Master of Science (Analytical Chemistry). Five complete samples are printed on this page so you can judge the writing before you ask for anything.
MCH 019 Guess Paper at a Glance
- 20 questions with answers
- 5 samples shown on this page
- 15 remaining in the full file
- 2 blocks 8 units covered
- 25 marks 1 hour paper
- 6 answers to write in the exam hall
- 4 sessions of past papers analysed
- Dec 2026 target session
What the MCH 019 Solved Guess Paper Covers for Green Chemistry
The file holds twenty questions on MCH 019 Green Chemistry, each written out in the pattern the Term-End answer sheet rewards: definition first, numbered points next, closing line last. Fifteen of those twenty are marked HIGH priority. Five are marked MEDIUM and kept as backup.
Five questions are written at the length of a five mark answer, which is the Question 1 or Question 2 slot. The other fifteen are written at four mark length, which is where Questions 3 to 8 sit. That split is deliberate. You will never be asked to write a 150 word answer for a four mark question, and padding is what costs students their last five minutes.
The topics run the full width of the course. From Block 1 you get atom economy against reaction yield, safer solvents and auxiliaries, designing safer chemicals, prevention with design for degradation and real time analysis, feedstock and reagent selection, evaluation of reaction types, catalysis with process analytical chemistry, and global climate change.
From Block 2 you get carbon dioxide as a solvent and the surfactant work of DeSimone, stratospheric ozone depletion, volatile organic compounds, the green route to ibuprofen, fouling with TBTO and DCOI, molting agents, paper production and chlorine free bleaching, TAML activators, expanded polystyrene, the Petretec process, scales with PAC and TPA, and microbes as benign catalysts.
If you are still gathering material for the wider programme, our IGNOU Solved Guess Paper library carries the same format across other course codes, so the way you learn one subject transfers to the next.
Sample Questions and Answers from the MCH 019 Green Chemistry Guess Paper
Five of the twenty answers are reproduced in full below, exactly as they appear inside the PDF. They are pulled from both blocks on purpose, so you are judging the writing across easy and hard territory rather than seeing the five simplest ones. The remaining fifteen answers stay in the file.
Question. Explain the concept of atom economy. How is it different from the reaction yield? Which types of reactions are atom economic and which are not? Give reasons.
Answer. Atom economy was proposed by Trost in 1991 to indicate the synthetic efficiency of a reaction.
Reaction yield is the product formed divided by the theoretical amount, multiplied by one hundred. It reports only the percentage of the desired product, so co-products, side products and waste are left out of the picture entirely.
Atom economy is the molecular mass of the desired product divided by the molecular mass of all the products, multiplied by one hundred. It counts every product, every unused reactant, every reagent and the solvent. That is why it is the wider and more honest measure.
Reactions which are atom economic
- Addition reactions. Reactants add to one another, so nothing is thrown away. Diels-Alder gives 100 per cent.
- Rearrangement reactions. Atoms are re-organised and all of them are used. Claisen gives 100 per cent.
Reactions which are not atom economic
- Substitution reactions. The displaced group becomes waste. Ester to amide gives only 65.41 per cent.
- Elimination reactions. A small molecule is thrown out. Hoffmann elimination gives 35.3 per cent, the least economic of the four.
Closing line. Atom economy can be worked out at the design stage itself, which lets a chemist compare two routes and pick the greener one before a single flask is filled.
Question. Explain stratospheric ozone depletion. Give the reactions involved. How is ozone layer depletion harmful to humans?
Answer. CFCs released as waste into the atmosphere reach the stratosphere, where UV-C rays from the Sun break them down into chlorine radicals.
Reactions involved
- CF2Cl2 + UV-C gives •CF2Cl + Cl•
- O3 + Cl• gives O2 + ClO•
- ClO• + O• gives Cl• + O2
The chlorine radical attacks ozone to give the ClO radical and oxygen. Step three hands the chlorine radical straight back, so steps two and three repeat without end. One radical keeps destroying ozone rather than being consumed.
Harm to humans
- UV-B reaches the surface. A thinner ozone layer lets UV-B radiation through to ground level.
- Disease. Increased UV radiation causes skin cancer and cataract in humans.
Closing line. Because a single chlorine radical destroys ozone again and again, CFCs had to be replaced rather than merely reduced.
Question. Give the scheme of reactions of green synthesis of ibuprofen starting from isobutyl benzene. Why is it greener than the original synthesis?
Answer. Ibuprofen is a non-steroidal anti-inflammatory drug. The original Boots synthesis started from isobutylbenzene and ran to six steps. The greener route reaches the same drug in three.
The three step green scheme
- Isobutylbenzene undergoes Friedel-Crafts acylation with acetic anhydride using HF.
- The ketone so obtained is reduced with H2 over Raney nickel.
- Reaction with carbon monoxide over a palladium catalyst yields ibuprofen.
Why the route is greener
- Better atom economy. The first scheme manages 40 per cent, this one reaches 77 per cent.
- Less of everything. Fewer steps means fewer chemicals, less time, fewer purifications and less waste.
- No stoichiometric waste. HF replaces aluminium chloride, which used to leave aluminium trichloride hydrate for landfill.
- Catalyst recovery. Raney nickel and palladium are recovered at each step and reused.
Closing line. Cutting six steps down to three is green chemistry in action, the same drug produced with far less waste behind it.
Question. Briefly explain the steps involved in the production of paper. What is chlorine free paper?
Answer. Wood contains about 70 per cent polysaccharides in the form of cellulose and hemicellulose, and the remaining 30 per cent is lignin, which holds those polysaccharides together.
Steps in making paper
- Wood to pulp. Raw wood is converted into pulp.
- Cutting and cooking. Logs are cut small and treated with sodium hydroxide and sodium sulphide, which depolymerise the lignin.
- Pulping result. Most of the lignin, between 80 and 90 per cent, is decomposed.
- Bleaching. Residual lignin leaves a brown colour and has to be removed for white paper.
Why elemental chlorine is a problem
- Chlorinated products. Chlorine bleaching chlorinates the aromatics in lignin, giving dioxins and furans.
- Health harm. These cause cancer and behavioural disorders in the next generation in animals.
- Food chain. They bioaccumulate in fatty tissue and biomagnify up the food chain.
Closing line. The EPA banned elemental chlorine in April 2001 and promoted chlorine dioxide instead, and paper bleached that way is called chlorine free paper.
Question. What is PET? Name the monomers used in its synthesis. Briefly explain the Petretec process and how the mixture of DMT and ethylene glycol obtained in it is separated.
Answer. PET is a polymer whose full form is polyethylene terephthalate. It was discovered in 1939 by W. H. Carothers of DuPont and sold as Dacron, Mylar and terylene. Its monomers are ethylene glycol and terephthalic acid, the latter converted to dimethyl terephthalate, or DMT.
The Petretec process
- Purpose. It converts waste PET back into DMT, which is then repolymerised to first quality PET.
- Dissolution. PET dissolves in DMT above 220 degrees Celsius.
- Methanolysis. Methanol is bubbled through at 260 to 300 degrees Celsius and 340 to 650 kPa.
How the mixture is separated
- The difficulty. DMT and ethylene glycol form a low boiling azeotrope.
- Add MPT. Methyl p-toluate is added and forms another azeotrope with ethylene glycol, boiling lower still.
- Distil and purify. That azeotrope is distilled off and the DMT left behind is purified by fractional distillation.
- Recover MPT. The distillate splits and the MPT rich phase is decanted and reused.
Closing line. Even dye contaminated PET waste, once treated as unrecyclable, is brought back to virgin quality by this route.
Those five are the proof. The other fifteen answers, including safer solvents, carbon dioxide surfactants, feedstock selection, TAML activators, expanded polystyrene, molting agents and the microbial route to adipic acid, sit inside the complete PDF. Message 9899436384 on WhatsApp with your enrolment number and course code to enquire about the full MCH 019 guess paper.
Want all 20 answers? WhatsApp 9899436384 with "MCH 019" and we will share the details.
Enquire on WhatsApp 9899436384Students who like reading the real paper alongside a guess paper usually pair this file with our IGNOU Previous Year Question Paper collection, because the phrasing of an actual Term-End question is often blunter than a textbook heading suggests.
Complete Question Index of the MCH 019 Guess Paper with Answers
All twenty questions are listed below with their mark weight, priority and last appearance, so you know precisely what is inside before you enquire. The five samples above are marked. The other fifteen are described but not reproduced.
| No. | Question topic | Marks | What the answer gives you | Last appeared | Priority |
|---|---|---|---|---|---|
| Q1 | Concept of atom economy | 5 | Trost 1991 definition, yield formula against atom economy formula, four reaction types with their percentages | Absent in last four sessions | HIGH |
| Q2 | Safer solvents and auxiliaries | 5 | Four harmful solvent classes named with their specific hazard, four safer alternatives including immobilised solvents | Dec 2025, Dec 2024 | HIGH |
| Q3 | Carbon dioxide as a solvent | 5 | Four advantages of carbon dioxide, source and supercritical use, DeSimone surfactant and the micelle mechanism | Absent in last four sessions | HIGH |
| Q4 | Designing safer chemicals | 5 | Three routes to lower toxicity plus the five literature checks to run before choosing a compound | Dec 2024 | MEDIUM |
| Q5 | Prevention, degradation and real time analysis | 5 | Three principle statements quoted in book language, with DDT and plastic persistence as the worked examples | Grouped principle question | HIGH |
| Q6 | Stratospheric ozone depletion | 4 | Three radical reaction steps, the chain explanation, and the two named human diseases (Sample 2 above) | June 2026, June 2025, Dec 2024 | HIGH |
| Q7 | Volatile organic compounds | 4 | Named examples, three advantages, the smog formation equation and damage to crops, rubber and fabric | June 2026, Dec 2025, Dec 2024 | HIGH |
| Q8 | Choosing feedstock and reagent | 4 | Six feedstock checks including transport hazard and renewability, then five reagent comparison grounds | June 2026, Dec 2025, June 2025 | HIGH |
| Q9 | Preferred types of reactions | 4 | Two reaction types to favour, three to minimise, and the argument for fewer steps and more catalysts | June 2026, Dec 2025, June 2025 | HIGH |
| Q10 | Green synthesis of ibuprofen | 4 | Three step scheme against the six step Boots route, with the 40 and 77 per cent figures (Sample 3 above) | June 2025 | MEDIUM |
| Q11 | Catalysts and process analytical chemistry | 4 | Five catalyst advantages, the transition metal caution, and a clean definition of process analytical chemistry | June 2025, Dec 2024 | MEDIUM |
| Q12 | Fouling, TBTO and DCOI | 4 | Three harms of fouling, TBTO half-life figures, and four reasons DCOI is the safer antifoulant | June 2026, Dec 2024 | HIGH |
| Q13 | Molting agents as safer insecticides | 4 | The 20-hydroxyecdysone hormone cycle, tebufenozide under the CONFIRM name, and the selectivity argument | Absent in last four sessions | HIGH |
| Q14 | Paper production and chlorine free paper | 4 | Four pulping and bleaching steps, dioxin and furan formation, and the EPA position (Sample 4 above) | Dec 2024 | HIGH |
| Q15 | Advantages of TAML activators | 4 | Terrence Collins attribution, five TAML advantages including the 50 against 120 degree figure, alternative bleaches | June 2025 | HIGH |
| Q16 | Expanded polystyrene and blowing agents | 4 | How EPS is produced, three reasons demand is rising, and the CFC-12, HCFC-22 and pentane problems | June 2026, Dec 2025 | HIGH |
| Q17 | PET and the Petretec process | 4 | Carothers attribution, monomer names, methanolysis conditions and the MPT azeotrope trick (Sample 5 above) | June 2026, Dec 2025 | HIGH |
| Q18 | Scales, PAC and TPA | 4 | Chemical identity of scales, five operating disadvantages, and the PAC against thermal polyaspartate comparison | June 2025, Dec 2024 | HIGH |
| Q19 | Global climate change | 4 | Greenhouse effect chain of cause, then seven consequences from heat waves through to ocean acidification | Dec 2025 | MEDIUM |
| Q20 | Microbes as benign catalysts | 4 | Frost and Draths attribution, four reasons benzene and toluene are dropped, the modified E. coli pathway | Dec 2025 | MEDIUM |
Five samples on this page plus fifteen in the file makes twenty. There is no hidden second volume and no upsell after the first message.
Block and Unit Coverage of MCH 019 Green Chemistry
MCH 019 is organised into two blocks holding eight units in total, and every one of those units contributes at least one question to this guess paper. The table below maps the official structure against what the file actually answers.
| Block | Unit | Unit title | Core ground the unit holds | Questions drawn |
|---|---|---|---|---|
| Block 1: Fundamentals of Green Chemistry | Unit 1 | Green Chemistry | The twelve principles stated in book language, prevention of waste, design for degradation, real time analysis for pollution prevention | Q1, Q5 |
| Block 1: Fundamentals of Green Chemistry | Unit 2 | Tools of Green Chemistry | Feedstock and starting material selection, reagent comparison, catalysis, auxiliary substances and the case for solvent avoidance | Q2, Q8, Q11 |
| Block 1: Fundamentals of Green Chemistry | Unit 3 | Evaluation of Chemical Products or Processes | Judging a synthetic route, ranking addition and rearrangement above substitution and elimination, designing lower toxicity into a molecule | Q4, Q9 |
| Block 1: Fundamentals of Green Chemistry | Unit 4 | Harmful Effects of Chemistry | Greenhouse effect and global climate change, smog and photochemical smog, toxicity to humans and wildlife | Q19 |
| Block 2: Applications of Green Chemistry | Unit 5 | Planning a Green Synthesis | Carbon dioxide as an alternative solvent, DeSimone surfactants for precision cleaning, the three step ibuprofen route, VOCs and ozone loss | Q3, Q6, Q7, Q10 |
| Block 2: Applications of Green Chemistry | Unit 6 | Towards Safer Environment | Marine antifoulants with TBTO and DCOI, molting agents and tebufenozide, genetically altered E. coli for adipic acid and catechol | Q12, Q13, Q20 |
| Block 2: Applications of Green Chemistry | Unit 7 | Using Safer Reagents | Pulping and bleaching in paper production, TAML activators for hydrogen peroxide, carbon dioxide as a blowing agent for EPS | Q14, Q15, Q16 |
| Block 2: Applications of Green Chemistry | Unit 8 | Greener Technologies | Polyester regeneration through the Petretec process, scale inhibition, polyacrylate against biodegradable thermal polyaspartate | Q17, Q18 |
Block and unit titles above follow the official IGNOU course structure published on eGyanKosh. Learners who want the underlying units alongside the answers can pick those up through our MCH 019 Study Material page and read them in the order the table sets out.
How the MCH 019 Important Questions Were Selected from Past Papers
Four Term-End papers were read question by question before a single answer was written: December 2024, June 2025, December 2025 and June 2026. Every question was tagged to a topic, and the tags were counted.
Three signals decided the priority of each topic. The first is repetition. A topic that surfaced in three or four of those sittings is close to certain and carries a HIGH tag. The second is absence. A topic central to the syllabus that has stayed quiet across all four sittings is treated as due, and also carries HIGH.
Atom economy, carbon dioxide surfactants and molting agents all sit in that second bucket, which is why they lead the file despite not appearing recently. The third signal is marks position, because a topic that keeps landing in the five mark slot is written to five mark length rather than four.
The frequency table on the last page of the PDF prints this working openly, one row per topic and one column per session, so you can see what the tag rests on rather than trusting a colour. Fifteen topics ended up HIGH and five ended up MEDIUM.
Answers themselves were written only from the IGNOU study material for Green Chemistry. That constraint matters more than it sounds. Examiners mark against the book, so a technically correct answer sourced from an outside textbook can still lose marks for using unfamiliar terminology. Names and figures are carried across exactly as the book gives them, DeSimone, Draths and Frost, Terrence Collins, 50 degrees Celsius, 40 and 77 per cent.
You can verify the pattern claims yourself against the official paper published by IGNOU at ignou.ac.in, which is where our December 2024 tagging started.
MCH 019 Green Chemistry Exam Pattern and One Hour Time Plan
The MCH 019 Term-End paper runs for one hour and carries 25 marks, and you write six answers in that hour: one worth five marks and five worth four marks each. That is roughly ten minutes per answer including reading time.
| Section | Instruction | Marks | Length to aim for |
|---|---|---|---|
| Question 1 or Question 2 | Answer any one of the two | 5 | About 150 words, definition plus four numbered points plus a closing line |
| Questions 3 to 8 | Answer any five of the six | 4 each | About 130 words, definition plus five to seven short numbered points |
| Total written | Six answers in all | 25 | Around 800 words across the full hour |
Three habits cost marks in this particular paper. Writing long introductions, when a four mark answer has no room for one. Attempting more than the required number of questions, which burns minutes without adding a single mark. And drawing structural formulae slowly when the reaction steps written in words would have scored the same.
The guess paper carries a short rules page ahead of the answers that sets out exactly this, along with a note on what not to memorise. Anyone preparing across several papers in the same programme will find the same structure in our MSCCHEM Guess Paper range, which follows one house format so revision habits carry over.
Who Should Use This MCH 019 Solved Guess Paper
This file is written for IGNOU learners registered in Master of Science (Chemistry) under MSCCHEM and Master of Science (Analytical Chemistry) under MSCANCHEM who have MCH 019 Green Chemistry in their Term-End form. It suits three situations in particular.
- Short on time. You have a fortnight or less and eight units to cross. The priority tags tell you which fifteen answers to learn first and which five to keep as backup.
- Reappearing in December 2026. You cleared the assignment but the theory paper did not go your way. Reading the same twenty answers twice is a smaller job than reading two blocks again.
- Strong on concept, weak on presentation. You understand green chemistry perfectly well but lose marks writing loosely. The definition-then-points-then-closing shape fixes that without new learning.
It is not a replacement for the study material. If you have never opened Block 1, twenty answers will not carry you through a full hour. Read the units, then use this to decide where your revision hours go.
How to Get the Full MCH 019 Guess Paper on WhatsApp
Send a WhatsApp message to 9899436384 with your name, enrolment number and the course code MCH 019, and we will reply with availability and the details for the December 2026 session. There is no account to create and no form to fill on this page.
- Message 9899436384 on WhatsApp mentioning MCH 019 Green Chemistry and your programme, MSCCHEM or MSCANCHEM.
- We confirm the session the file is prepared for and answer any question you have about coverage.
- Once your enquiry is complete, the PDF is delivered to the same WhatsApp number, ready to read on a phone.
Enquiries are usually answered within a few hours on working days. If you need the paper for more than one course code in the same programme, mention all of them in the first message and we will handle them together.
Ready to prepare properly for December 2026? All 20 answers, both blocks, one file.
WhatsApp 9899436384 NowMCH 019 Green Chemistry Guess Paper FAQs
How many questions are in the MCH 019 Solved Guess Paper?
The MCH 019 file carries twenty questions in total, each with a complete written answer underneath it. Five of those answers are printed in full on this page as samples, which leaves fifteen inside the PDF. Five questions are written at five mark length and the remaining fifteen at four mark length, matching the two sections of the Term-End paper exactly.
Which session is the MCH 019 guess paper prepared for?
This edition targets the December 2026 Term-End Examination and remains usable for June 2027, since the Green Chemistry syllabus and the twenty five mark structure have not changed across recent sittings. The frequency analysis behind it runs to June 2026, so the June 2026 paper is part of the input rather than a session the file is aimed at.
How many previous year papers were analysed for MCH 019 Green Chemistry?
Four Term-End papers were read and tagged question by question: December 2024, June 2025, December 2025 and June 2026. Every question was mapped to a syllabus topic and the counts were tabulated one row per topic. That table is printed on the final page of the PDF, so the HIGH and MEDIUM priority tags can be checked against the underlying sessions.
Does the MCH 019 guess paper cover both blocks of Green Chemistry?
Yes. Block 1 on Fundamentals of Green Chemistry and Block 2 on Applications of Green Chemistry are both covered, and all eight units contribute at least one question. Unit 5 carries the heaviest load with four questions, while Unit 4 on harmful effects of chemistry contributes one. The block and unit table on this page shows the full mapping.
Is MCH 019 Green Chemistry a theory paper or does it have a practical file?
MCH 019 is a theory course assessed through a one hour Term-End paper of twenty five marks, together with one tutor marked assignment. There is no separate practical or laboratory file attached to this course code. Laboratory work in MSCCHEM and MSCANCHEM sits under separate lab course codes, so nothing practical is needed for MCH 019 preparation.
Will the same questions appear in the MCH 019 Term-End examination?
No guess paper can promise that, and we do not. What this MCH 019 file does is rank topics by how often they have actually appeared and how long they have been absent, then write a complete answer for each. Students who learn all twenty are prepared for the shape and the language of the paper, which is where most marks are recovered.
How do I receive the MCH 019 guess paper after enquiring?
Delivery happens over WhatsApp on 9899436384. Send your name, enrolment number and the code MCH 019, and you will get a reply confirming availability for December 2026 along with the details. The file arrives as a single PDF that opens on any phone, so no printing or desktop software is needed to start revising immediately.