01Solutions
7 marksColligative properties, and almost always a numerical — molality, elevation of boiling point, depression of freezing point, or a van’t Hoff factor question.
Class 12 · Chemistry · 043
All of this exists free somewhere. It's spread across a syllabus PDF, a dozen blogs that copy each other's mistakes, and a hundred channels. Here it is in one place, with what I'd actually do.
What I got in this subject
My worst paper, and the one I have most to say about. It was evaluated at 51.5, rounded to 52, and moderation took it to 59 — the biggest jump of my five subjects. I am not going to pretend I did this one well.
70 marks of theory across 10 units · 33 questions · 3 hours
Colligative properties, and almost always a numerical — molality, elevation of boiling point, depression of freezing point, or a van’t Hoff factor question.
The heaviest unit in the paper, and the one the 2026 paper leaned on hardest. Nernst equation, cell EMF, conductivity and molar conductivity, and electrolysis calculations.
Rate law and order, the first-order integrated rate equation, half-life, and Arrhenius. Reliably numerical.
Reason-based questions: why this oxidation state, why that colour, why this magnetic moment. Lanthanoid contraction turns up constantly.
IUPAC naming, isomerism, and crystal field theory — hybridisation, geometry, magnetic behaviour. Very predictable once you have done thirty of them.
SN1 versus SN2 reasoning, reactivity order, and named conversions.
Distinction tests, acidity comparisons, and mechanism-flavoured conversions.
The biggest organic unit. Named reactions, distinguishing tests, and a conversion chain almost every year.
Basicity order with reasons, diazotisation, and identification tests.
Almost pure recall — carbohydrates, proteins, vitamins, nucleic acids. The cheapest marks in the paper.
Organic is 26 of the 70. Physical is 23. Inorganic is 14, and Biomolecules is 7 on its own. If you are short on time, that ordering is your ordering — and it is not the order the textbook is in, which is why people who study front-to-back run out of time inside Physical and never give Organic a proper pass.
Biomolecules is the anomaly worth exploiting. Seven marks, essentially no problem-solving, almost entirely recall. It is the single best marks-per-hour unit in the subject and it is routinely left until the night before, at which point people are too tired to memorise anything.
Electrochemistry is nine marks on its own — more than any other unit — and it is where the 2026 paper concentrated. It is also the unit most people are weakest at, because it is the one where the numericals actually bite.
If you have one week: Biomolecules, then Organic, then Electrochemistry. In that order.
I only found this by adding up my own evaluated script. Chemistry had eleven half-marks in it — more than any of my other four papers, which had ten, four, two and none. Physics is the only other one that comes close.
That tells you something about how the subject is marked. Long answers are broken into small scoring points and a half mark is awarded for each fragment you got — the correct reagent, the correct condition, the balanced equation, the right final product. You are not being awarded a mark for a good answer. You are being awarded fragments.
The practical consequence is that a half-finished organic conversion is worth real marks and a beautifully explained wrong answer is worth none. Write the reagent above the arrow even if you cannot finish the chain. Write the condition. Balance the equation even if the mechanism defeated you.
Never leave an organic conversion blank. Write the reagents you are sure of — they are separately worth half a mark each.
My script says 51.5 out of 70 before rounding, which is not a good score, and I know exactly what caused it: I treated Chemistry as the subject I would deal with later, all year, and later turned out to be about four days.
Organic was the part that survived, because it is pattern-based and patterns can be crammed. Physical was where I bled — the numericals need to have been done before, and you cannot acquire that in a week. That maps almost exactly onto what the 2026 cohort reported: organic scoring, physical numericals tricky.
If I were doing it again the only change I would make is doing Electrochemistry and Kinetics numericals through the year instead of in the last week. Not the whole subject. Just the numericals, because they are the only part that does not respond to cramming.
The syllabus was rationalised and a meaningful amount of Class 12 Chemistry is no longer examinable. Older question banks, older one-shots and most YouTube playlists still contain it, so you can lose a genuine weekend studying topics that cannot be asked.
I am deliberately not listing the deleted topics here, because the lists that circulate on coaching sites contradict each other and I have not verified any of them against the source. Open CBSE’s own rationalised curriculum PDF and check your chapter against it before you start. It takes two minutes and it is the highest-value two minutes in your preparation.
Verify against cbseacademic.nic.in, not against a blog. Including this one.
Two channels, not twenty. Both checked by hand — plenty of dead accounts carry exactly the name you'd expect.
What I actually used, for both Physics and Chemistry. Full chapters, free, explained slowly enough to stick.
The second opinion when Ashu sir’s explanation is not landing. Two people explaining the same chapter differently is often what makes it click.
Checked against CBSE Academic — curriculum and rationalised syllabus · NCERT textbooks. Weightage is CBSE's own and is checked at build time to sum to 70.
Reading a guide is the same trap as watching a one-shot — it feels like work and produces nothing on its own. Set a daily question target and start today; the number compounds much faster than it feels like it should.