Every October session, learners go looking for a NIOS Class 12 Chemistry 313 Solved TMA that actually walks through the reasoning instead of handing over one-line answers. This page carries the full October 2026 tutor marked assignment for subject code 313, the complete question list exactly as it appears on the paper, two fully worked sample answers so you can judge the quality before you decide, and a straightforward way to get the complete solved file on WhatsApp.
Written by Prateek Talwar. Reviewed by Jyoti Sharma, Senior NIOS Counsellor. Last updated: 18 July 2026.
Nothing here is lifted from a generic guidebook. Our answers are drafted after reading the current NIOS Chemistry textbook module by module, then checked against the marking pattern so each response stays inside the word limit the paper asks for.
NIOS Class 12 Chemistry 313 Solved TMA 2026 at a Glance
The Chemistry (313) tutor marked assignment carries real weight. Across NIOS, the TMA component contributes 40 per cent of your internal marks for the subject, so a clean, correct submission lifts your overall result before you even sit the theory paper. The October 2026 paper has six question blocks, and each block lets you attempt any one of the two options given.
The assignment spans short reasoning answers of 40 to 60 words, longer explanatory answers of 100 to 150 words, and a project style question with several sub-parts. Our solved file answers every option, not only the ones we picked for the samples below, so you can choose whichever version suits your handwriting speed and understanding.
If you are also collecting papers for other subjects this session, the same team maintains the wider NIOS Solved TMA range, so you can keep one point of contact for every code you are enrolled in.
Complete List of Chemistry 313 TMA Questions for October 2026
Here is the full question paper for the Chemistry 313 assignment, renumbered in a clean sequence and tagged with the NIOS lesson each question is drawn from. Seeing the lesson map helps you revise the exact topics before you copy anything down.
Question 1, Lesson 3, Periodic Table and Periodicity in Properties (attempt any one, 40 to 60 words)
- (a) Classify the elements of group 14, 15 and 16 into metals, non-metals and metalloids.
- (b) Compare the metallic character of aluminium and potassium.
Question 2, Lesson 8, Colloidal State (attempt any one, 40 to 60 words)
- (a) Why does the application of alum to a fresh cut wound help stop bleeding?
- (b) Two beakers A and B contain ferric hydroxide sol and NaCl solution respectively. When a beam of light is allowed to converge on them in a darkened room, the beam is visible in beaker A but not in beaker B. Give the reason. What is this effect called?
Question 3, Lesson 10, Spontaneity of Chemical Reactions (attempt any one, 40 to 60 words)
- (a) In the given chemical reactions, indicate whether you would expect the entropy of the system to increase or decrease: (i) 2SO₂ (g) + O₂ (g) → 2SO₃ (g); (ii) N₂ (g) + 3H₂ (g) → 2NH₃ (g).
- (b) Give reasons: (i) neither heat (q) nor work (w) is a state function but q + w is a state function; (ii) a real crystal has more entropy than an ideal crystal.
Question 4, Lesson 32, Environmental Chemistry (attempt any one, 100 to 150 words)
- (a) Write down the reactions involved during the formation of photochemical smog.
- (b) Write down the reactions involved for ozone layer depletion in the stratosphere.
Question 5, Lesson 19, p-Block Elements and Their Compounds-I (attempt any one, 100 to 150 words)
- (a) Explain the pattern of variation in the oxidation states of (i) B to Tl and (ii) C to Pb.
- (b) Consider the compounds BCl₃ and CCl₄. How will they behave with water? Justify your answer.
Question 6, Lesson 30, Drugs and Medicines (prepare any one project)
- (a) A World Health Day health camp case study on Dr. Satpal and the NHRC, with sub-parts on the values shown, the antihistamines used for hay fever, and a suitable artificial sweetener for diabetic patients.
- (b) A case study on Mr. Naresh and sleeping pills, with sub-parts on the values shown by his friend, the class of drugs used in sleeping pills, and why self-medication with sleeping pills is unsafe.
Sample Answers from the Chemistry 313 Solved TMA
Rather than describe our quality in the abstract, here are two answers pulled straight from the solved file, one short reasoning answer and one longer analytical answer. Read them the way an evaluator would and see whether the logic holds together.
Sample 1, Question 1(a): Classify the elements of group 14, 15 and 16.
Group 14: Carbon, silicon (non-metals); germanium (metalloid); tin, lead (metals). Group 15: Nitrogen, phosphorus (non-metals); arsenic, antimony (metalloids); bismuth (metal). Group 16: Oxygen, sulfur, selenium (non-metals); tellurium (metalloid); polonium (metal). Thus, non-metals dominate the upper members, metalloids occur in the middle, and metallic nature increases down the groups due to larger size, lower ionisation energy, and stronger metallic bonding.
Sample 2, Question 5(a): Pattern of variation in oxidation states, B to Tl and C to Pb.
(i) In Group-13, the common oxidation state is +3. Boron forms only covalent compounds and never shows B³⁺ because of the high ionisation energy required. Aluminium is metallic and shows stable +3 state. Gallium, indium and thallium also show +3, but due to the inert pair effect, the +1 state becomes increasingly stable in heavier members. In fact, thallium prefers +1 oxidation state, while +3 is less stable. Thus, the trend shifts from stable +3 in lighter members (B, Al) to increasing preference for +1 in heavier ones (In, Tl).
(ii) In Group-14, carbon and silicon stably show +4 oxidation state, forming covalent compounds. Germanium, tin and lead show both +2 and +4 states. The inert pair effect stabilises the +2 state as we move down the group. Lead mainly exhibits +2 oxidation state, while +4 becomes less stable. Hence, the trend shifts from +4 (C, Si) to +2 predominance (Pb).
The remaining answers, including the reaction sequences for photochemical smog and ozone depletion and the full project write-up, follow the same standard in the complete file.
How We Prepare the NIOS Class 12 Chemistry 313 Solved TMA
Preparation starts with the current 313 textbook, not last year's notes. Chemistry gets revised more often than people expect, so we open the latest edition on the NIOS portal and match every question in the paper to its exact lesson before drafting a single line.
For a short answer, we keep it tight and inside the 40 to 60 word band, because an over-long answer to a short-answer question tends to lose the crisp point an evaluator is scanning for. For the 100 to 150 word questions, we build a clear opening statement, then the mechanism or reactions, then a one-line consequence, which is the structure that reads as a complete answer.
Because Chemistry sits alongside your other papers, we treat the assignment as part of a larger revision plan rather than an isolated task. If you want to organise your reading around it, our broader NIOS Study Material library covers notes and past papers for the same code, so the assignment reinforces what you revise for the theory exam.
Chemistry 313 TMA Marking Scheme and Submission Rules
The tutor marked assignment is graded internally and folded into your final Chemistry result. In the NIOS scheme the TMA holds 40 per cent weightage while the public examination holds the remaining 60 per cent, so neglecting the assignment quietly caps the marks you can reach overall.
You are expected to write the assignment in your own handwriting, attempt the required number of questions from each block, and submit it to your allotted study centre or AI before the cut-off notified for the October session. Keep a photocopy of the completed assignment for your own record until your marks are confirmed.
If the whole tutor marked assignment idea is new to you, our explainer on what a NIOS TMA is walks through the submission flow, the weightage, and the common mistakes learners make with word limits and question choice.
All Chemistry 313 Lessons Covered in the NIOS Syllabus
The Chemistry 313 course runs to 32 lessons across eight modules. Twelve of those lessons are the ones NIOS assigns to the TMA, and the current 313 assignment draws its questions from six of them. The table below lists every lesson and marks whether it belongs to the TMA set or the public examination set, so you can see at a glance where your assignment topics sit.
| Lesson | Lesson Name | Module | Assessment |
|---|---|---|---|
| 1 | Atoms, Molecules and Chemical Arithmetic | I: Some Basic Concepts of Chemistry | Public Exam |
| 2 | Atomic Structure | II: Atomic Structure and Chemical Bonding | Public Exam |
| 3 | Periodic Table and Periodicity in Properties | II: Atomic Structure and Chemical Bonding | TMA |
| 4 | Chemical Bonding | II: Atomic Structure and Chemical Bonding | Public Exam |
| 5 | The Gaseous State and Liquid State | III: States of Matter | TMA |
| 6 | The Solid State | III: States of Matter | TMA |
| 7 | Solutions | III: States of Matter | Public Exam |
| 8 | Colloidal State | III: States of Matter | TMA |
| 9 | Chemical Thermodynamics | IV: Chemical Energetics | Public Exam |
| 10 | Spontaneity of Chemical Reactions | IV: Chemical Energetics | TMA |
| 11 | Chemical Equilibrium | V: Chemical Dynamics | TMA |
| 12 | Ionic Equilibrium | V: Chemical Dynamics | Public Exam |
| 13 | Electrochemistry | V: Chemical Dynamics | Public Exam |
| 14 | Chemical Kinetics | V: Chemical Dynamics | TMA |
| 15 | Adsorption and Catalysis | V: Chemical Dynamics | TMA |
| 16 | Occurrence and Extraction of Metals | VI: Chemistry of Elements | TMA |
| 17 | Hydrogen and s-Block Elements | VI: Chemistry of Elements | Public Exam |
| 18 | General Characteristics of p-Block Elements | VI: Chemistry of Elements | Public Exam |
| 19 | p-Block Elements and Their Compounds-I | VI: Chemistry of Elements | TMA |
| 20 | p-Block Elements and Their Compounds-II | VI: Chemistry of Elements | Public Exam |
| 21 | d-Block and f-Block Elements | VI: Chemistry of Elements | Public Exam |
| 22 | Coordination Compounds | VI: Chemistry of Elements | Public Exam |
| 23 | Nomenclature and General Principles | VII: Chemistry of Organic Compounds | Public Exam |
| 24 | Hydrocarbons | VII: Chemistry of Organic Compounds | Public Exam |
| 25 | Compounds of Carbon Containing Halogens | VII: Chemistry of Organic Compounds | Public Exam |
| 26 | Alcohols, Phenols and Ethers | VII: Chemistry of Organic Compounds | Public Exam |
| 27 | Aldehydes, Ketones and Carboxylic Acids | VII: Chemistry of Organic Compounds | Public Exam |
| 28 | Compounds of Carbon Containing Nitrogen | VII: Chemistry of Organic Compounds | Public Exam |
| 29 | Bio-molecules | VII: Chemistry of Organic Compounds | Public Exam |
| 30 | Drugs and Medicines | VIII: Chemistry in Everyday Life | TMA |
| 31 | Soaps, Detergents and Polymers | VIII: Chemistry in Everyday Life | Public Exam |
| 32 | Environmental Chemistry | VIII: Chemistry in Everyday Life | TMA |
Anyone planning their subjects across the senior secondary stage should note that the same lesson-mapped approach runs through the whole course, and the NIOS Class 12 Syllabus is laid out the same way when you are mapping out the year ahead.
Why Students Choose Our Chemistry 313 Solved TMA
What sets this file apart is that every option is answered and every answer respects the word limit. Learners tell us the biggest time drain is not understanding the chemistry, it is deciding which option to attempt and then trimming an answer to fit. We remove both problems by solving all options cleanly.
The answers also stay faithful to the textbook's terminology, which matters because evaluators recognise the phrasing they are trained to look for. You get correctness and the right vocabulary, so a well-copied submission reads like considered work rather than a rushed paraphrase.
Students handling more than one submission with us often pick up the NIOS Class 12 Solved TMA in the same conversation, which keeps every subject on a single, consistent support system.
How to Get the Chemistry 313 Solved TMA on WhatsApp
Delivery is deliberately simple. Message us on WhatsApp with your subject code, 313, and the session you need, October 2026, and we will confirm availability, share the format, and send the complete solved file. Most learners receive their file the same day they reach out.
Get the Chemistry 313 Solved TMA on WhatsApp (9654 279 279). Alternate line: 9899 436 384.
If you need the file in a specific medium or want handwritten pages instead of a typed copy, mention it in your first message so we can set it up correctly from the start.
Frequently Asked Questions on NIOS Chemistry 313 Solved TMA
Is the NIOS Chemistry 313 Solved TMA updated for the October 2026 session?
Yes. The file is prepared specifically for the October 2026 tutor marked assignment using the current 313 question paper. Every question block is matched to its lesson in the latest NIOS Chemistry textbook, and the answers follow this session's word limits and question choices rather than being carried over from an earlier year. We refresh it whenever the paper changes.
Does the Chemistry 313 Solved TMA answer every question or only a few?
The solved file answers every option in all six question blocks, not only the two we display as samples. Since each block lets you attempt any one option, having both options solved means you can pick whichever answer suits your handwriting speed and comfort with the topic before you copy it down. That flexibility is why the full file beats a partial key.
How much does the Chemistry 313 tutor marked assignment count towards my result?
The tutor marked assignment carries 40 per cent weightage in your internal Chemistry marks, while the public examination carries the remaining 60 per cent. A complete, correctly written submission therefore lifts your overall standing before the theory paper. Submitting late or leaving it half done simply lowers the ceiling on the final grade you can reach in the subject.
Can I get the Chemistry 313 Solved TMA as handwritten pages?
Yes, handwritten versions are available alongside the typed file. Mention that you want handwritten pages in your first WhatsApp message so the request is set up correctly. Handwritten copies are useful if you are short on time before the submission deadline or prefer to hand in ready-made pages at your study centre. The answer content stays identical to the typed version.
Which lessons does the current NIOS Class 12 Chemistry TMA cover?
This session's Chemistry assignment draws its questions from six TMA lessons: the Periodic Table, the Colloidal State, Spontaneity of Chemical Reactions, p-Block Elements, Environmental Chemistry, and Drugs and Medicines. The lesson table above maps each question to its exact lesson, so you can revise the right topics first and avoid wasting time on chapters this paper does not touch.
How quickly will I receive the Chemistry 313 Solved TMA after paying?
Most learners receive the file the same day they message us. Once you confirm the subject code and session on WhatsApp, we share the format and send the complete solved assignment. If you need a particular medium or a handwritten copy, that is arranged during the same conversation. Payment and delivery both happen inside that single chat, so nothing extra is needed.
Disclaimer: Unnati Educations is an independent academic support platform and is not affiliated with, endorsed by, or officially connected to the National Institute of Open Schooling (NIOS). Subject codes, lesson names, and assignment references belong to their respective owners and are used only to help learners locate the correct study material.
Sources: NIOS Senior Secondary Chemistry (313) bifurcated syllabus and official study material, nios.ac.in.
