Playbooks
12 chapter playbooks behind every NDA Chemistry question
One playbook per chapter (subtopics are well-cleaned but thin — per-subtopic playbooks would proliferate without adding clarity). Grouped by the strategic axis that matters: Recall / Rule / Calculate.
- playbooks
- 12
- questions covered
- 262
- skill strands
- 3
- years analysed
- 10
Recall — Carbon · Matter · Industrial · Metals · Hydrogen · Everyday · Practical
Pure fact recall — chemical names, formulas, uses, allotropes, alloy compositions. 7 chapters, 144 questions, 4% average HARD. The marks-per-hour leader. 144 q total.
Carbon and Its Compounds
45 q · 4% HARD — the largest chapter. Allotropes (15 q · diamond/graphite/fullerene/graphene), common organic compounds (10 q), functional groups (9 q), soaps + hydrogenation, catenation, hydrocarbons. Pure recall + functional-group pattern recognition.
45 q · 4% hard deep diveMatter and Its States
30 q · 3% HARD. Five subtopics: separation techniques (filtration, distillation, chromatography), compound/mixture/solution classification, states + phase change, colloids vs suspensions (20% HARD — the lone trap subtopic), and physical vs chemical change identification.
30 q · 3% hard deep diveIndustrial and Applied Chemistry
28 q · 11% HARD. Industrial gases (water gas, producer gas, syngas), cement + glass composition, fertilisers (NPK), alloys (brass, bronze, solder, stainless steel), and paints + coatings (4 q · 75% HARD — the bank's most concentrated HARD pool, pigment/drier/thinner/anti-skinning).
28 q · 11% hard deep diveMetals and Non-Metals
17 q · 0% HARD. Reactivity series (K > Na > Ca > Mg > Al > Zn > Fe > Cu > Hg > Ag > Au), reactions with water/acids, corrosion + galvanisation, alloy compositions, and ore-extraction methods. Zero HARD across the chapter — drill it for guaranteed marks.
17 q · 0% hard deep diveHydrogen and Water
11 q · 9% HARD. Permanent vs temporary hardness (CaSO₄/MgSO₄ vs Ca(HCO₃)₂), softening methods (boiling/ion-exchange/lime-soda), pure-water source ranking, and dihydrogen properties + storage. The 'permanent hardness can't be removed by boiling' trap recurs.
11 q · 9% hard deep diveChemistry in Everyday Life
10 q · 0% HARD. Common chemicals + their uses (deep-sea diver's gas, freezing mixtures, fire-extinguisher CO₂, household acids), and medicines (antacids, analgesics, antibiotics). Pure recall — every q is a 'which substance does X' match.
10 q · 0% hard deep divePractical Chemistry
3 q · 0% HARD in 10 years. Lab + food + health applications (food preservation, toothpaste action, curd-keeping methods). Read once, recognise, done — under 20 min total.
3 q · 0% hard deep dive
Rule — Atomic Structure · Acids/Bases/Salts · Reactions · Bonding
Apply specific rules — pH classification, oxidation-state assignment, periodic-trend prediction, redox identification. 4 chapters, 109 q at 7% average HARD. 109 q total.
Atomic Structure and Periodic Classification
35 q · 9% HARD. Periodic trends (atomic radius, ionisation energy, electronegativity — across vs down), valency from group number, atomic-number/mass-number/subatomic-particle arithmetic, atomic models (Dalton → Thomson → Rutherford → Bohr — what each PROVED, not just what they said), isotopes vs isobars vs isoelectronic.
35 q · 9% hard deep diveAcids, Bases and Salts
33 q · 6% HARD. pH-scale classification (acidic < 7, neutral = 7, basic > 7), common-acid recall (citric in lemons, oxalic in tomatoes, lactic in milk, acetic in vinegar), Arrhenius/Brønsted/Lewis theory comparisons, oxides (acidic/basic/amphoteric/neutral), salts (acidic/basic/normal), and water of crystallisation counts.
33 q · 6% hard deep diveChemical Reactions
30 q · 10% HARD. Redox classification (oxidation = loss of e⁻ / OIL RIG mnemonic), reaction-type identification (combination, decomposition, displacement, double-displacement), specific reactions (precipitation, electrolysis, lime water + CO₂), thermal decomposition products, and endo/exothermic recognition.
30 q · 10% hard deep diveChemical Bonding
11 q · 0% HARD. Ionic vs covalent prediction from electronegativity difference, oxidation-state assignment in a compound (rule sequence: H = +1, O = −2, group I = +1, sum to zero), valency from electronic config, molecular formula → atom count. Pure rule application, every q tractable.
11 q · 0% hard deep dive
Calculate — Mole Concept and Stoichiometry
Numeric work — mole/Avogadro/equivalent-weight/stoichiometry. 1 chapter, 9 q at 11% HARD. Small but distinct skill — don't skip. 9 q total.