MCH 019 June 2026 key facts
- Course code: MCH-019
- Subject: Green Chemistry
- Programme: M.Sc. Chemistry (MSCCHEM) and M.Sc. Analytical Chemistry (MSCANCHEM), Semester II
- Credits: 2 (theory)
- Blocks and units: 2 blocks, 8 units
- Maximum marks (TEE): 25
- Duration: 1 hour
- Questions in the paper: 8 printed; you attempt 6 (Q1 or Q2, plus any five of Q3 to Q8)
- Samples shown on this page: 2 (Q1 and Q4)
- Questions in the paid file: All 8, including 6 not shown on this page
What the MCH 019 Solved Question Paper June 2026 Includes
MCH 019 Solved Question Paper June 2026 covers all 8 questions of the official IGNOU Green Chemistry term-end exam, with answers sized for its 25-mark, one-hour format.
MCH 019 Green Chemistry is a 2-credit, Semester II theory course of the IGNOU M.Sc. Chemistry (MSCCHEM) and M.Sc. Analytical Chemistry (MSCANCHEM) programmes, offered by the School of Sciences.
The June 2026 paper is short but full of choices. You answer Q1 or Q2 for 5 marks, then any five of Q3 to Q8 at 4 marks each. That is six answers in sixty minutes, so each one has to state the key idea, show an equation or structure where it helps, and name one real industrial case quickly.
This page shows two of those answers in full: Q1 on reducing unnecessary derivatisation and Q4 on choosing between elimination, addition and redox reactions. The other six questions, on VOCs, reagent choice, ozone depletion, fouling, the EPS blowing agent and the Petretec process, are answered only in the full file.
If you are collecting every MSCCHEM Question Paper for Semester II, keep this one next to the December 2024 paper, because ozone depletion, antifouling agents and a principle-based 5-mark question appear in both.
MCH 019 Green Chemistry Sample Answers for Q1 and Q4
Two June 2026 MCH 019 answers are shown below in full, Q1 (5 marks) and Q4 (4 marks), each written to the length an examiner expects in this one-hour paper.
Question 1
Q1. Explain the principle of ‘reducing unnecessary derivatisation’ of green chemistry. Discuss the purposes of derivative formation in the chemistry laboratories. Describe the implications of derivative formation. (5 marks)
Answer
Meaning of the principle. Reducing unnecessary derivatisation is the eighth of the twelve principles of green chemistry proposed by Paul Anastas and John Warner in 1998. It says that blocking or protecting groups, protection and deprotection steps, and any temporary modification of a molecule should be minimised or avoided wherever possible, because each such step needs extra reagents and produces extra waste.
Purposes of derivative formation in the laboratory. Chemists make derivatives for four main reasons:
- Protection: a reactive group is masked so that a reagent attacks only the intended site. An alcohol is turned into a silyl ether (for example a TBDMS ether), an amine into its Boc carbamate, or a ketone into an acetal before a Grignard or hydride step.
- Activation: a poor leaving group is converted into a better one, such as a carboxylic acid into its acid chloride with SOCl2, or an alcohol into a tosylate, so that substitution can take place.
- Isolation and identification: a salt (such as an amine hydrochloride) or a crystalline derivative (such as a 2,4-dinitrophenylhydrazone of a carbonyl compound) helps separate, purify or identify a compound.
- Analysis: silylation gives trimethylsilyl derivatives that are volatile enough for gas chromatography, and tagging with a chromophore improves UV detection in HPLC.
Implications of derivative formation. From a green chemistry point of view, each derivatisation has a cost:
- More steps: every protect, react and deprotect sequence adds at least two steps, each with its own solvent, energy input, work-up and yield loss.
- Poor atom economy and more waste: atoms of the protecting or activating group never reach the final product, so they leave as waste and raise the E-factor (kg of waste per kg of product).
- Hazardous reagents: many derivatising agents, such as acid chlorides and silyl chlorides, are corrosive, moisture-sensitive or toxic, adding risk and disposal cost.
- Higher cost and time: extra purification and longer process time make the product more expensive.
Example of the principle at work. Industrial production of 6-aminopenicillanic acid (6-APA) from penicillin G once needed the carboxyl group to be protected as a silyl ester, followed by treatment with PCl5 at about −40 °C in dichloromethane. The enzyme penicillin acylase now removes the side chain in water close to room temperature, with no protecting group at all.
Conclusion. The principle asks chemists to use selective catalysts, especially enzymes, or to redesign the route, instead of adding a temporary group only to remove it later.
Question 4
Q4. Which type of reaction from the following will you prefer for synthesizing a particular compound ? (i) Elimination reaction. (ii) Addition reaction. (iii) Oxidation-reduction reaction. Give reasons in support of your answer. (4 marks)
Answer
Preferred choice: (ii) Addition reaction. An addition reaction can place every atom of the reactants into the product, so it can reach 100% atom economy with no stoichiometric by-product. This matches the green chemistry principle of atom economy.
Atom economy (%) = (molar mass of desired product ÷ total molar mass of all reactants) × 100
(ii) Addition. In the Diels-Alder reaction, buta-1,3-diene (C4H6, 54.09 g/mol) adds to ethene (C2H4, 28.05 g/mol) to give cyclohexene (C6H10, 82.14 g/mol). Atom economy = 82.14 ÷ 82.14 × 100 = 100%. Catalytic hydrogenation of an alkene with H2 is also an addition and is equally efficient.
(i) Elimination. Elimination always splits off a small molecule that becomes waste. In the dehydrobromination CH3CHBrCH3 + NaOH → CH3CH=CH2 + NaBr + H2O, atom economy = 42.08 ÷ (122.99 + 40.00) × 100 ≈ 25.8%. About three-quarters of the reactant mass ends up as NaBr and water.
(iii) Oxidation-reduction. Classical redox reactions use stoichiometric oxidising or reducing agents whose spent forms are waste and are often toxic. Oxidising propan-2-ol with acidified dichromate, 3C3H8O + K2Cr2O7 + 4H2SO4 → 3C3H6O + Cr2(SO4)3 + K2SO4 + 7H2O, gives an atom economy of only about 20% and leaves chromium salts to dispose of. Redox steps become greener only when a catalyst works with O2, H2O2 or H2.
Conclusion. For synthesising a particular compound, an addition route is the first choice. Elimination and stoichiometric redox steps should be used only when no addition route exists, and redox steps should then be made catalytic.
Questions answered only in the full file
The 6 questions below are printed exactly as they appear in the June 2026 paper. Their answers are not shown on this page.
Q2. What are VOCs ? Give two examples. List three advantages of VOCs. Also give their harmful effects. (5 marks)
Q3. What aspects should be kept in mind while we choose a reagent for a particular synthesis ? How would you compare the available reagents from green chemistry point of view ? (4 marks)
Q5. Explain stratospheric ozone depletion. Also discuss its harmful effects. (4 marks)
Q6. What is fouling ? Discuss its harmful effects. (4 marks)
Q7. What were the problems associated with the use of pentane as a blowing agent in manufacture of EPS ? What was the solution proposed for resolving this issue ? (4 marks)
Q8. How is the mixture of DMT and ethylene glycol, obtained in the Petretec process separated ? Briefly explain the steps involved. (4 marks)
MCH 019 Block and Unit Syllabus at a Glance
MCH 019 Green Chemistry is studied in 2 blocks and 8 units: Block 1 builds the principles and tools, and Block 2 applies them to real industrial products and processes.
| Block | Unit | Key topics |
|---|---|---|
| Block 1: Fundamentals of Green Chemistry | Unit 1: Green Chemistry | Need and origin of green chemistry; the twelve principles; Presidential Green Chemistry Challenge Awards (from 1996) |
| Block 1: Fundamentals of Green Chemistry | Unit 2: Tools of Green Chemistry | Selecting starting materials, reagents and reaction types; catalysis; process analytical chemistry |
| Block 1: Fundamentals of Green Chemistry | Unit 3: Evaluation of Chemical Products or Processes | Toxicity and safety checks before using a compound; judging products and processes for human and environmental safety |
| Block 1: Fundamentals of Green Chemistry | Unit 4: Harmful Effects of Chemistry | Toxicity to humans and wildlife; local effects such as smog and photochemical smog; global effects such as ozone layer depletion and global warming |
| Block 2: Applications of Green Chemistry | Unit 5: Planning a Green Synthesis | Green synthesis of ibuprofen compared with the Boots route; surfactants for carbon dioxide in precision cleaning |
| Block 2: Applications of Green Chemistry | Unit 6: Towards Safer Environment | Microbes as benign catalysts for adipic acid, catechol and BHT; safe marine antifoulants; molting agents to replace harmful insecticides |
| Block 2: Applications of Green Chemistry | Unit 7: Using Safer Reagents | Replacing the blowing agent in EPS manufacture; oxidant activators for hydrogen peroxide in paper bleaching |
| Block 2: Applications of Green Chemistry | Unit 8: Greener Technologies | PET uses and its monomers; the Petretec process; greener manufacture of terephthalic acid |
The unit titles come from the IGNOU self-learning material for MCH-019. Note that the 2026 assignment booklet refers to four blocks, while the published study material is arranged as two blocks of four units each.
Block 2 is where most 4-mark questions come from, because each unit is built around a named industrial case. Read those case units first if you are short of time, and use our MCH 019 Study Material to revise the Block 1 principles alongside them.
MCH 019 Exam Pattern, Choices and Marks Split
The MCH 019 question paper carries 25 marks in 1 hour: one 5-mark question from a choice of two, plus five 4-mark questions from a choice of six.
| Section | Questions printed | You answer | Marks each | Marks total |
|---|---|---|---|---|
| Long answer (either/or) | Q1, Q2 | 1 | 5 | 5 |
| Short answers | Q3 to Q8 | 5 | 4 | 20 |
| Total | 8 | 6 | - | 25 |
With roughly ten minutes per answer, the paper rewards precise definitions, one balanced equation or calculation, and a named example. Long background paragraphs cost time without adding marks.
Several June 2026 questions follow the wording of the December 2024 paper and the 2026 assignment closely, so checking each IGNOU Previous Year Question Paper for this course is one of the fastest ways to predict what comes next.
Repeated MCH 019 Topics in Official Green Chemistry Papers
Six MCH 019 topic areas appeared in both official papers we checked, December 2024 and June 2026, which makes them the safest topics to prepare first.
| Topic | December 2024 | June 2026 | Times asked |
|---|---|---|---|
| Principle-based 5-mark question (one of the twelve principles) | Q1 (designing chemical products) | Q1 (reducing derivatisation) | 2 |
| Stratospheric ozone depletion | Q2 (role of CFCs) | Q5 | 2 |
| Fouling and antifouling agents | Q6 (DCOI compared with TBTO) | Q6 | 2 |
| Choosing safe compounds and reagents | Q4 (literature checks on safety) | Q3 | 2 |
| Air pollutants: smog and VOCs | Q5 (smog and photochemical smog) | Q2 | 2 |
| Tools: catalysis and choice of reaction | Q3 (catalysts, process analytical chemistry) | Q4 | 2 |
| Paper production and bleaching | Q7 | Not asked | 1 |
| Scale formation and scale inhibitors | Q8 | Not asked | 1 |
| Blowing agent in EPS manufacture | Not asked | Q7 | 1 |
| PET recycling and the Petretec process | Not asked | Q8 | 1 |
This count uses only the two official IGNOU MCH 019 Question Paper sets we checked line by line. The course is new, so the list of past papers is still short, and the pattern will become clearer with each session.
Notice that the 2026 assignment also asks about paper bleaching, the Petretec process and EPS, so topics asked once are not low priority. For a ranked revision list across courses, see our IGNOU Important Questions page.
How Our MCH 019 Answers Are Written and Checked
Every MCH 019 answer is written from the IGNOU study blocks, sized to the marks printed against the question, and checked for chemistry and arithmetic before it goes into the file.
Our author, Prateek Talwar, maps each question to its unit first, so the answer uses the same cases and terms the IGNOU material uses. A 5-mark answer runs to about 300 words, and a 4-mark answer to about 220 to 280 words, which is what you can realistically write in ten minutes.
Equations are balanced and molar masses are worked through, as in the atom economy figures in the Q4 sample. Where a question names an industrial process, the answer gives the steps in order, because examiners mark sequence as well as content.
Sheetal Kirola then reviews each answer against the question wording, so that every part is answered. That is the same standard you see in the two samples above, and it applies to the whole IGNOU MCH 019 Solved Question Paper.
MCH 019 Solved File Index by Question and Unit
The full MCH 019 file answers all 8 June 2026 questions; this index shows which unit each one comes from and whether its answer appears on this page.
| Question | Topic | Marks | Course unit | Where to find the answer |
|---|---|---|---|---|
| Q1 | Principle of reducing unnecessary derivatisation | 5 | Unit 1 | On this page |
| Q2 | VOCs: examples, advantages, harmful effects | 5 | Unit 4 (partly) | Full file only |
| Q3 | Choosing and comparing reagents | 4 | Unit 2 | Full file only |
| Q4 | Preferred reaction type: elimination, addition or redox | 4 | Unit 2 | On this page |
| Q5 | Stratospheric ozone depletion and its effects | 4 | Unit 4 | Full file only |
| Q6 | Fouling and its harmful effects | 4 | Unit 6 | Full file only |
| Q7 | Pentane as EPS blowing agent and the proposed fix | 4 | Unit 7 | Full file only |
| Q8 | Separating DMT and ethylene glycol in the Petretec process | 4 | Unit 8 | Full file only |
MCH 019 is a theory-only course, so there is no practical record for it; laboratory work in Semester II sits in the separate MCHL-014, MCHL-015 and MCHL-016 courses. That is why this index lists questions and units instead of experiments.
Programmes That Include MCH 019 Green Chemistry
MCH 019 Green Chemistry is a Semester II course shared by two IGNOU School of Sciences programmes, MSCCHEM and MSCANCHEM.
In the IGNOU Master of Science (Chemistry) programme, MCH 019 sits beside MCH-016 Inorganic Chemistry-II, MCH-017 Organic Chemistry-II and MCH-018 Quantum Chemistry and Group Theory in Semester II.
M.Sc. Analytical Chemistry (MSCANCHEM) learners take the same MCH 019 Green Chemistry paper, which is why both codes are printed on it. You can confirm the course and its credits on the official IGNOU MSCCHEM programme page.
Get the Full MCH 019 Solved Question Paper on WhatsApp
To get the full MCH 019 Solved Question Paper June 2026, message us on WhatsApp at 9899436384; the PDF answers all 8 questions, including the 6 not shown on this page.
- Save 9899436384 and open WhatsApp.
- Send the message: MCH 019 June 2026.
- Our team confirms the price and shares the solved PDF.
The file has the same layout you see in the preview pages: question text exactly as printed, the marks for each question, and a full answer with headings, equations and examples from the MCH 019 units.
MCH 019 Green Chemistry FAQs
What does the MCH 019 Solved Question Paper June 2026 contain?
It contains all 8 questions from the official June 2026 MCH 019 Green Chemistry paper with complete, exam-length answers. Two answers, Q1 on reducing unnecessary derivatisation and Q4 on choosing between elimination, addition and redox reactions, are shown on this page. The remaining six, covering VOCs, reagent choice, ozone depletion, fouling, EPS and the Petretec process, are in the full PDF.
How do I get the full MCH 019 June 2026 answers on WhatsApp?
Send a WhatsApp message to 9899436384 with the words MCH 019 June 2026. Our team will confirm the price and share the complete solved PDF, which has answers to all 8 questions: the 2 shown on this page plus the 6 that appear here as question text only. You can also ask about other Semester II MSCCHEM courses in the same chat.
How many questions must I attempt in the MCH 019 Green Chemistry exam?
You attempt six questions in total. The MCH 019 paper asks you to answer either Q1 or Q2 for 5 marks, then any five out of Q3 to Q8, each worth 4 marks. That adds up to 25 marks in one hour, so you have roughly ten minutes per answer and need short, structured responses with equations where they help.
Which MCH 019 topics repeat most often in official papers?
Across the December 2024 and June 2026 MCH 019 papers, six topic areas appeared in both: a principle-based 5-mark question, stratospheric ozone depletion, fouling and antifouling agents, choosing safe compounds or reagents, air pollutants such as smog and VOCs, and tools like catalysis and reaction choice. Paper bleaching, scale inhibitors, EPS and the Petretec process each appeared once.
Are the MCH 019 answers written to IGNOU word limits?
Yes. Our MCH 019 answers are sized for a one-hour, 25-mark paper, so 5-mark answers run to roughly 300 words and 4-mark answers to roughly 220 to 280 words. Each answer opens with a direct definition or statement, then adds balanced equations, worked atom economy figures or named industrial examples from the IGNOU study blocks where the question needs them.
Is MCH 019 Green Chemistry common to MSCCHEM and MSCANCHEM?
Yes. MCH 019 Green Chemistry is a Semester II theory course in both the IGNOU M.Sc. Chemistry (MSCCHEM) and M.Sc. Analytical Chemistry (MSCANCHEM) programmes, and the June 2026 paper prints both programme codes. Learners from either programme sit the same 25-mark, one-hour term-end exam, so this solved paper and its sample answers suit both groups of learners equally well.
How many credits and units does MCH 019 Green Chemistry carry?
MCH 019 carries 2 credits as a theory course. Its IGNOU study material is organised into two blocks: Block 1, Fundamentals of Green Chemistry, with Units 1 to 4, and Block 2, Applications of Green Chemistry, with Units 5 to 8. The assignment carries 30 per cent weightage, and you must submit it before filling in the exam form.
Can I judge the full MCH 019 file from the two sample answers?
Yes, that is why they are here. The full MCH 019 file follows the same pattern as the Q1 and Q4 answers on this page: a direct opening line, clear headings, balanced equations or calculations where relevant, and an industrial example tied to the study blocks. If the samples match how you like to revise, the other six answers will too.