🧪 रसायन विज्ञान (Chemistry)

📌 0. Exam Pattern & 2025 Analysis (2 min read)

• MP Police SI Prelims mein Vigyan (Science) ke 10 sawal aate hain: Physics 4 + Chemistry 3 + Biology 3. Yani Chemistry = har shift mein 3 sawal.
• Official 2025 paper (16–21 Jan 2026, 12 shifts) ke 36 Chemistry sawalon ka analysis:
  • Atomic structure + Periodic table — sabse zyada (~14 sawal): amu, isotopes, valency, quantum numbers, spectral series, electronegativity, dipole moment.
  • Polymers (~6): Teflon, nylon, polycarbonate, elastomer, starch plastic, wool-silk.
  • Soap / micelle (~3), Surface chemistry & kinetics (~5), Biomolecules & drugs (~4), d-block (KMnO₄) (~2), organic naming (~3).
• ⚠️ Level sirf class 10 tak nahi hai — kai sawal NCERT class 11-12 ke concept se aaye. Isliye is page mein har topic ke saath "Advanced (11-12) quick facts" bhi diye gaye hain.

📌 1. पदार्थ, मिश्रण व कोलॉइड (Matter, Mixtures & Colloids) (6 min read)

1.1 पदार्थ की अवस्थाएँ (States of Matter)

• Jo bhi jagah gherta hai aur jiska mass hai = पदार्थ (Matter). Teen common states: ठोस (Solid) — fixed shape & volume; द्रव (Liquid) — fixed volume, shape nahi; गैस (Gas) — na shape, na volume (sabse zyada compressible).
• प्लाज़्मा (Plasma) = 4th state — bahut garam, ionised gas. Suraj/taare, neon sign ke andar.
• Bose-Einstein Condensate (BEC) = 5th state — bahut kam temperature par. Naam Indian scientist सत्येन्द्र नाथ बोस aur Einstein ke naam par.
• Particles ke beech attraction: Solid > Liquid > Gas. विसरण (Diffusion) gas mein sabse tez.

1.2 अवस्था परिवर्तन (Change of State)

• Evaporation badhta hai: temperature ↑, surface area ↑, hawa (wind) ↑, humidity ↓.
• Pressure cooker: pressure badhne se paani ka boiling point badh jata hai → khana jaldi pakta hai. Pahad par hawa ka pressure kam → paani 100°C se kam par ubalta hai → khana der se pakta hai.
• Paani mein namak milane se boiling point badhta hai aur freezing point ghatta hai (isliye sadkon par barf pighlane ke liye namak).

1.3 भौतिक व रासायनिक परिवर्तन (Physical vs Chemical Change)

1.4 शुद्ध पदार्थ व मिश्रण (Pure Substances & Mixtures)

• तत्व (Element): ek hi prakar ke atom — Fe, O₂, Na. यौगिक (Compound): tatva fixed anupaat mein chemically jude — H₂O, NaCl, CO₂ (properties apne tatvon se alag).
• मिश्रण (Mixture): koi fixed anupaat nahi, ghatak apne gun rakhte hain.
  • समांगी (Homogeneous): poora ek jaisa — namak ka ghol, hawa, alloys (brass), soda water.
  • विषमांगी (Heterogeneous): — ret + paani, tel + paani, doodh-mein-cornflakes.
• विलयन (Solution) — particles sabse chhote, Tyndall effect nahi. निलंबन (Suspension) — particles bade, neeche baith jaate hain (keechad wala paani, chalk-paani). कोलॉइड (Colloid) — beech ka size, particles neeche nahi baithte, टिंडल प्रभाव (Tyndall effect) dikhate hain (light ka bikharna — jungle mein pedon ke beech se aati dhoop ki kiran).

1.5 कोलॉइड के प्रकार (Types of Colloids — examples yaad karo)

• Emulsion todna (Demulsification): garam karke, jamaakar (freezing) ya अपकेंद्रीकरण (Centrifugation) se. Emulsion ko stable rakhne wala = emulsifier (jaise soap, protein).

1.6 मिश्रण अलग करने की विधियाँ (Separation Techniques)

📌 2. परमाणु संरचना (Atomic Structure) (8 min read) — 2025 mein sabse zyada sawal

2.1 मौलिक कण व उनके खोजकर्ता (Sub-atomic Particles)

2.2 परमाणु मॉडल (Atomic Models)

• Dalton (1808): atom avibhajya (indivisible) — baad mein galat sabit hua.
• Thomson model: "Plum pudding / tarbooz model" — positive gola, usme electrons dhanse hue.
• Rutherford α-kan prakeernan prayog (Gold foil experiment): patli sone ki panni par α-particles (+ve) maare:
  • Zyadatar seedhe nikal gaye → atom ka zyadatar hissa khaali hai.
  • Kuch bade kon (large angle) par mude → beech mein chhota, bhaari, positive nucleus hai jo α-kan ko प्रतिकर्षण (repulsion) se modta hai.
  • Bahut kam (NCERT: lagbhag 12000 mein 1) seedhe wapas laute.
  • Kami: ghoomte electron energy khokar nucleus mein gir jaane chahiye the — stability explain nahi kar paya.
• Bohr model (1913): electrons fixed कक्षा / कोश (orbits/shells) K, L, M, N mein ghoomte hain; har shell ki fixed energy. Shell mein max electrons = 2n² (K=2, L=8, M=18, N=32).

2.3 परमाणु संख्या, द्रव्यमान संख्या, समस्थानिक (Z, A, Isotopes)

• परमाणु संख्या (Atomic number, Z) = protons ki sankhya (neutral atom mein = electrons). Concept: Henry Moseley (1913).
• द्रव्यमान संख्या (Mass number, A) = protons + neutrons. Neutrons = A − Z.
• समस्थानिक (Isotopes): same Z, alag A → neutron alag. Chemical properties same (kyunki electron same). Hydrogen ke 3: प्रोटियम ¹H (0 neutron), ड्यूटेरियम ²H / D (1 neutron — heavy water D₂O), ट्रिटियम ³H (2 neutron, radioactive). Carbon: C-12, C-13, C-14 (C-14 radioactive — carbon dating). Chlorine: Cl-35, Cl-37.
• समभारिक (Isobars): same A, alag Z — ⁴⁰Ar aur ⁴⁰Ca. समन्यूट्रॉनिक (Isotones): same neutrons.
• ⚠️ Fluorine ka prakriti mein sirf ek hi stable isotope (F-19) hota hai (monoisotopic element); isliye "kiska isotope nahi hota" type sawal mein answer Fluorine (Hydrogen, Carbon, Chlorine sabke kai isotopes hain).

2.4 परमाणु द्रव्यमान इकाई व मोल (amu & Mole)

• Atomic mass unit (amu / u) = ek C-12 atom ke mass ka 1/12 bhaag ≈ 1.66 × 10⁻²⁷ kg. Atomic mass isi mein likhte hain (kg/gram mein nahi).
• मोल (Mole): 1 mole = 6.022 × 10²³ particles (Avogadro number). Mole = SI base unit (amount of substance).
• Molar mass: H₂O = 2(1) + 16 = 18 g/mol; CO₂ = 12 + 2(16) = 44 g/mol; NaCl = 23 + 35.5 = 58.5 g/mol.

2.5 संयोजकता (Valency)

• Valency = sabse bahari kosh (outermost shell / valence shell) ke electrons se tay hoti hai — atom kitne electron dega/lega/share karega taaki 8 (octet) poore ho jaayein.
• Outer electrons 1-4 → valency = utne hi; 5-7 → valency = 8 − electrons. Examples: Na (2,8,1) → 1; Mg → 2; Al → 3; C → 4; N (2,5) → 3 (NH₃ mein N ki valency 3); O (2,6) → 2; Cl (2,8,7) → 1; noble gases → 0.

2.6 Advanced (11-12) quick facts — Quantum numbers & Spectrum

• Rules: Aufbau (kam energy wala orbital pehle bharta hai), Pauli (ek orbital mein max 2 electron, ulte spin), Hund (pehle har orbital mein ek-ek, phir pairing).
• Hydrogen spectrum series (jis level par electron girkar khatam hota hai):
  Lyman → n = 1 (UV) | Balmer → n = 2 (visible) | Paschen → n = 3 (IR) | Brackett → n = 4 (IR) | Pfund → n = 5 (IR).
  Trick: "Lucky Boy Played Badminton Properly" = 1, 2, 3, 4, 5.

📌 3. आवर्त सारणी व रासायनिक बंधन (Periodic Table & Bonding) (7 min read)

3.1 आवर्त सारणी का इतिहास (History)

• डोबेराइनर के त्रिक (Döbereiner's Triads): 3-3 tatvon ke group — Li, Na, K; Ca, Sr, Ba; Cl, Br, I (beech wale ka atomic mass = baaki do ka ausat).
• न्यूलैंड्स का अष्टक नियम (Newlands' Octaves): har 8wa tatva pehle jaisa (sangeet ke sur jaisa) — sirf Calcium tak sahi.
• मेंडेलीफ़ (Mendeleev, 1869): tatvon ko atomic mass ke kram mein rakha; us samay ke 63 tatva; khaali jagah chhodi aur naye tatvon ki bhavishyavani ki — eka-boron (Scandium), eka-aluminium (Gallium), eka-silicon (Germanium). "Father of Periodic Table".
• आधुनिक आवर्त नियम (Modern Periodic Law) — Henry Moseley (1913): tatvon ke gun unke atomic number ka periodic function hain.
• Modern table: 18 groups (vertical) aur 7 periods (horizontal); aaj 118 tatva. Blocks: s, p, d, f. Lanthanides & Actinides (f-block) neeche alag.

3.2 प्रमुख समूह (Important Groups)

• उपधातु (Metalloids): B, Si, Ge, As, Sb, Te — dhatu aur adhatu dono ke gun (Si, Ge = semiconductors).

3.3 आवर्ती प्रवृत्तियाँ (Periodic Trends)

• Electronegativity = bond mein shared electrons ko apni taraf kheenchne ki kshamta. Fluorine sabse zyada electronegative (Pauling scale 4.0) → sabse "adhatvik" (most non-metallic) tatva. Order: F > O > N ≈ Cl.
• इलेक्ट्रॉन बंधुता (Electron affinity) = electron jodne par nikli energy. Sabse zyada Chlorine (Fluorine nahi — chhote size ke kaaran F mein electron-electron repulsion). Nitrogen ki electron affinity lagbhag shunya — kyunki uska aadha-bhara p-orbital (2p³) extra stable hai. Noble gases ki bhi lagbhag shunya/positive.
• Sabse zyada ionisation energy: Helium.

3.4 रासायनिक बंधन व ध्रुवता (Chemical Bonding & Polarity)

• आयनिक बंध (Ionic bond): electron ka transfer (dhatu → adhatu) — NaCl, MgO. Ucch melting point, paani mein ghulte hain, pighalne/ghulne par current chalate hain.
• सहसंयोजी बंध (Covalent bond): electrons ki sajhedari (sharing) — H₂, Cl₂, CH₄, H₂O. Single (H–H), double (O=O), triple (N≡N).
• हाइड्रोजन बंध (H-bond): H + bahut electronegative atom (F, O, N) — isse paani ka boiling point zyada, barf paani par tairti hai, DNA ki do strands judti hain, protein ki α-helix stable rehti hai.
• द्विध्रुव आघूर्ण (Dipole moment, μ = q × d, unit Debye): polarity ka maap. Symmetrical molecules mein dipoles cancel → μ = 0 (non-polar): CO₂ (linear), BeCl₂, BF₃ (trigonal planar), SO₃, CH₄, CCl₄, XeF₄ (square planar).
  Polar (μ ≠ 0): H₂O (bent), NH₃ (pyramidal), HCl, CHCl₃, SF₄ (see-saw shape, 1 lone pair).
• Methyl halides ka dipole moment: CH₃Cl > CH₃F > CH₃Br > CH₃I. (F sabse electronegative par C–F bond chhota hai, isliye CH₃Cl sabse upar.)

📌 4. रासायनिक अभिक्रियाएँ, उत्प्रेरक व अधिशोषण (Reactions, Catalysts & Adsorption) (7 min read)

4.1 अभिक्रियाओं के प्रकार (Types of Reactions — NCERT Class 10)

• ऑक्सीकरण (Oxidation): oxygen judna / hydrogen hatna / electron khona. अपचयन (Reduction): oxygen hatna / hydrogen judna / electron lena. Jo khud reduce hokar doosre ko oxidise kare = oxidising agent.
• संक्षारण (Corrosion): lohe par जंग (Rust = Fe₂O₃·xH₂O) — iske liye hawa (O₂) aur nami (paani) dono chahiye. Chandi kaali (silver sulphide), taamba hara (basic copper carbonate). Bachav: paint, tel/grease, जस्तीकरण (Galvanisation = zinc ki parat), alloy (stainless steel).
• विकृतगंधिता (Rancidity): tel/ghee wala khana oxidise hokar badboodaar. Bachav: antioxidants, airtight dabba, chips ke packet mein nitrogen gas, fridge.

4.2 अभिक्रिया की दर व उत्प्रेरक (Rate & Catalyst)

• Rate badhta hai: concentration ↑, temperature ↑, surface area ↑ (powder jaldi react karta hai), उत्प्रेरक (Catalyst).
• Catalyst rate badhata hai par khud khatam nahi hota; ye सक्रियण ऊर्जा (Activation energy) kam karta hai (naya, aasaan raasta deta hai). Enzymes = jaiv-utprerak (biocatalysts).
• दर-निर्धारण चरण (Rate-determining step): multi-step reaction mein sabse dheema step — yani jiski activation energy sabse zyada ho. Wahi poori reaction ki speed tay karta hai.

4.3 Advanced (12): अधिशोषण (Adsorption)

• Adsorption = kisi padarth ke kano ka doosre ki sirf satah (surface) par jama hona (charcoal gases ko sokhta hai — gas mask). Absorption = poore andar tak (sponge mein paani).

• Langmuir adsorption isotherm ki maanyataayein: (1) satah ke saare adsorption sites ek jaise (equivalent/homogeneous); (2) sirf ek parat (monolayer); (3) adsorbed anuon ke beech koi interaction nahi.

📌 5. अम्ल, क्षार एवं लवण (Acids, Bases & Salts) (8 min read)

5.1 मूल बातें (Basics)

• Neutralisation (उदासीनीकरण): Acid + Base → Salt (लवण) + Water.
• Acid + dhatu → lavan + H₂ gas (jalti tilli paas laane par "pop" awaaz). Acid + carbonate/bicarbonate → lavan + CO₂ + paani (CO₂ choone ke paani / lime water ko doodhiya karti hai).
• ⚠️ Acid ko patla karte samay acid ko paani mein daalo, paani ko acid mein nahi (bahut garmi nikalti hai, chhinte ud sakte hain).

5.2 सूचक (Indicators)

• Olfactory (gandh) indicators: pyaaz, vanilla, laung — base mein inki gandh gayab.

5.3 pH स्केल (pH Scale)

• pH = "potenz" (German: shakti) of H⁺; scale 0–14; S.P.L. Sørensen (1909) ne diya. pH < 7 acidic, = 7 neutral (shuddh paani), > 7 basic. pH 1 kam hone par H⁺ concentration 10 guna badhta hai.

• Daant (teeth): muh ka pH 5.5 se neeche jaane par enamel (calcium hydroxyapatite — sharir ka sabse kathor padarth) ghulne lagta hai → tooth decay. Toothpaste basic hota hai.
• अम्लीय वर्षा (Acid rain): baarish ka pH 5.6 se kam (SO₂, NOₓ se).
• Pet mein acidity: antacid — milk of magnesia Mg(OH)₂ ya baking soda.
• Mitti: zyada acidic mitti mein quicklime (CaO) / slaked lime (Ca(OH)₂) / chalk milaate hain; zyada basic mitti mein organic matter (khaad).
• Keet ka dank: cheenti/bichhu-booti (nettle) ke dank mein मेथेनोइक (फॉर्मिक) अम्ल → baking soda jaise halke base se aaram.

5.4 प्राकृतिक अम्ल (Natural Acids — must memorise)

5.5 दैनिक जीवन के लवण (Everyday Salts — NCERT Class 10)

📌 6. धातु, अधातु, अयस्क व मिश्रधातु (Metals, Non-metals, Ores & Alloys) (8 min read)

6.1 धातु बनाम अधातु (Properties)

6.2 अपवाद (Exceptions — sabse zyada pooche jaate hain)

• पारा (Mercury, Hg) — room temperature par द्रव (liquid) dhatu. ब्रोमीन (Br) — liquid adhatu.
• Gallium, Caesium — itna kam melting point ki hatheli par pighal jaate hain.
• Sodium, Potassium — itne naram ki chaaku se kat jaate hain; hawa mein aag pakad lete hain, isliye kerosene mein rakhte hain. White phosphorus hawa mein jalta hai → paani mein rakhte hain.
• Iodine — adhatu hokar bhi chamakdaar. Graphite — adhatu hokar bhi bijli ka chaalak. Diamond — sabse kathor prakritik padarth, bahut ucch melting point.
• Gold, Silver — sabse zyada malleable/ductile (1 g sone se ~2 km lamba taar). Lead, Mercury — garmi ke kamzor chaalak.
• Tungsten — dhatuon mein sabse ucch melting point → bulb ka filament. Lithium — sabse halki dhatu. Osmium — sabse ghani (densest) dhatu.
• Prithvi ki parat (crust) mein: sabse zyada tatva Oxygen, phir Silicon; sabse zyada dhatu Aluminium, phir Iron.
• Aluminium oxide (Al₂O₃), Zinc oxide (ZnO) = उभयधर्मी (amphoteric) — acid aur base dono se react.

6.3 सक्रियता श्रेणी (Reactivity Series)

K > Na > Ca > Mg > Al > Zn > Fe > Pb > [H] > Cu > Hg > Ag > Au
Trick: "Kaise NahaCar Mgan Ali Znak Feke Pbar Hota Cuchh Hg Ag Au".
• H se upar wali dhatuen dilute acid se H₂ nikaalti hain; Cu, Hg, Ag, Au nahi.
• अम्लराज (Aqua regia) = 3 bhaag conc. HCl + 1 bhaag conc. HNO₃ — sona (Au) aur platinum bhi ghol deta hai.

6.4 धातुकर्म (Metallurgy — short)

• खनिज (Mineral) = prakriti mein mila yaugik; अयस्क (Ore) = jis khanij se dhatu labh ke saath nikale. Faltu mitti-ret = गैंग (gangue).
• भर्जन (Roasting): sulphide ore ko zyada hawa mein garam karna. निस्तापन (Calcination): carbonate ore ko kam/bina hawa mein garam karna.
• Kam reactive (Hg, Cu) — sirf garam karke; madhyam (Zn, Fe, Pb) — carbon se reduction; bahut reactive (Na, Mg, Ca, Al) — electrolysis se.
• Thermite reaction: Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + bahut garmi → railway patri jodna.
• Electrolytic refining: ashuddh dhatu = anode, shuddh patli patti = cathode.

6.5 प्रमुख अयस्क (Important Ores)

📍 MP link: मलाजखंड (बालाघाट) — desh ki sabse badi open-cast copper khadaan; पन्ना — heera (diamond) khadaan (Majhgawan).

6.6 मिश्रधातुएँ (Alloys)

• Alloy ki bijli chalakta aur melting point, shuddh dhatu se kam hota hai.
• 24 carat = shuddh sona (naram). 22 carat = 22 bhaag sona + 2 bhaag copper/silver (~91.6%).

6.7 Advanced (12): d-block — KMnO₄

• पोटैशियम परमैंगनेट (KMnO₄, "lal dawa") — gehra baingani. Mn ki oxidation state +7 (d⁰) hai, yani d-d transition sambhav nahi; rang aata hai charge transfer (oxygen → manganese) se.
• Lab mein Mn²⁺ ko MnO₄⁻ mein oxidise karne ke liye peroxodisulphate (S₂O₈²⁻) use hota hai.
• KMnO₄: strong oxidising agent, paani/kuen ka disinfectant. K₂Cr₂O₇ — narangi (orange).
• Transition dhatuen: rangeen yaugik, variable oxidation states, catalyst (Fe, Ni, Pt, V₂O₅).

📌 7. कार्बन यौगिक, साबुन व डिटर्जेंट (Carbon Compounds, Soaps & Detergents) (8 min read)

7.1 कार्बन की विशेषताएँ व अपररूप (Carbon & Allotropes)

• Carbon ki valency 4 (चतुःसंयोजकता / tetravalency); khud se lambi chains banane ka gun = शृंखलन (Catenation) → isliye lakhon carbon yaugik.
• Carbon covalent bond banata hai (4 electron dena/lena mushkil).

Amorphous (akristaliya) roop: koyla, charcoal (kaashth koyla), coke, lamp black.

7.2 हाइड्रोकार्बन (Hydrocarbons)

• Saturated hydrocarbon neeli (saaf) lau se jalte hain; unsaturated peeli, dhuen wali lau se.
• Benzene C₆H₆ — aromatic ring. Do substituents ki position: ortho = 1,2; meta = 1,3; para = 1,4. Jaise para-dichlorobenzene = 1,4-dichlorobenzene.

7.3 क्रियात्मक समूह (Functional Groups)

• एस्टरीकरण (Esterification): acid + alcohol → ester + paani (acid catalyst).
• साबुनीकरण (Saponification): ester (tel/charbi) + NaOH → sabun + glycerol/alcohol.
• Advanced (12): Gabriel phthalimide synthesis se sirf primary aliphatic amines bante hain (ethylamine, n-propylamine, benzylamine). Aromatic amines (aniline) aur tert-butylamine nahi bante (aryl halide / tertiary halide SN2 reaction nahi karte; tertiary halide elimination karta hai).

7.4 साबुन व अपमार्जक (Soaps & Detergents)

• साबुन (Soap) = lambi chain wale fatty acids ke sodium/potassium lavan (Na → kathor sabun, K → naram/liquid sabun).
• अपमार्जक (Detergent) = lambi chain ke sulphonate ya ammonium lavan. Kathor paani (hard water) mein bhi kaam karte hain; sabun kathor paani (Ca²⁺, Mg²⁺) ke saath scum (मैल / अवक्षेप) bana deta hai.
• Sabun ka anu: ek sira आयनिक / जलरागी (ionic, hydrophilic — –COO⁻Na⁺) → paani ki taraf; doosra lamba हाइड्रोकार्बन पूँछ / जलविरागी (hydrophobic) → tel/mael ki taraf.
• मिसेल (Micelle): paani mein sabun ke anu gola banaate hain — poonchh andar (tel/mael pakadti hai), ionic sira bahar paani ki taraf. Mael micelle ke beech mein phans kar paani ke saath beh jaata hai.
• Advanced (12): Micelle sirf ek nishchit concentration (CMC — Critical Micelle Concentration) se upar aur ek nishchit temperature (Krafft temperature, T_k) se upar banti hai. Isliye bahut thande paani mein sabun ki safai kam ho jaati hai. Micelle ke liye zaroori: paryapt concentration, non-polar poonchh, polar solvent (paani) — kam temperature zaroori nahi.

📌 8. प्रमुख रसायन, ईंधन व उर्वरक (Common Chemicals, Fuels & Fertilizers) (8 min read)

8.1 सामान्य नाम व रासायनिक सूत्र (Common Names & Formulas)

• 📍 MP link — भोपाल गैस त्रासदी (2–3 Dec 1984): Union Carbide factory se मिथाइल आइसोसाइनेट (MIC) gas ka rissaav — duniya ki sabse badi audyogik durghatnaon mein se ek.
• Aansu gas (Tear gas) — police dwara bheed niyantran: aaj mukhyatah CS aur CN (chloroacetophenone) gas.
• Monosodium glutamate (MSG / Ajinomoto) — swaad badhane wala; Sodium benzoate — khane ka preservative.

8.2 ईंधन (Fuels)

• ऊष्मीय मान / कैलोरी मान (Calorific value) = 1 kg ईंधन पूरा jalne par nikli ऊष्मा (kJ/kg). Accha ईंधन: zyada calorific value, sasta, aasaani se uplabdh, kam dhuaan/pradushan, ज्वलन ताप (ignition temperature) theek-thaak.

• LPG — mukhyatah butane (+ propane); gandh-heen hoti hai, leak pakadne ke liye ethyl mercaptan milaate hain. CNG — mukhyatah methane. Biogas — methane (NCERT: ~75% tak) + CO₂; gobar gas plant anaerobic (bina oxygen) bacteria se.
• Water gas = CO + H₂; Producer gas = CO + N₂; Coal gas = H₂ + CH₄ + CO.
• कोयले के प्रकार (Carbon % badhte kram mein): पीट (Peat) < लिग्नाइट (Lignite) < बिटुमिनस (Bituminous) < एन्थ्रेसाइट (Anthracite — sabse uttam). Mrit vanaspati ka laakhon saalon mein dheere-dheere koyle mein badalna = carbonisation (NCERT Class 8).
• Coal se: coke (lagbhag shuddh carbon — steel banane mein), coal tar (naphthalene golian, rang, visphotak, itra), coal gas.
• Petroleum ("kaala sona") refinery mein fractional distillation → LPG, petrol, kerosene, diesel, lubricating oil, paraffin wax, bitumen (sadak).
• Octane number — petrol ki "knocking" rokne ki kshamta (zyada = behtar). Diesel ke liye cetane number.
• Adhoora jalna → CO (carbon monoxide) — zehreeli, rang-gandh heen; haemoglobin se judkar oxygen le jaana rok deti hai (band kamre mein angithi khatarnaak).
• Lau (flame) ke kshetra (NCERT 8): sabse bahari — neela, sabse garam, poorn dahan (sunaar yahi use karta hai); beech — peela, chamakdaar, aanshik dahan; sabse andar — kaala, bina jali mom ki vaashp.
• Aag bujhana: bijli ya tel ki aag par paani nahi — CO₂ extinguisher sabse accha (oxygen ki supply kaat deta hai, upkaran kharab nahi karta).

8.3 उर्वरक (Fertilizers)

• Paudhon ke mukhya poshak: N, P, K (nitrogen, phosphorus, potassium).
• यूरिया — CO(NH₂)₂ — sabse zyada nitrogen (~46%). Ammonia (Haber process) + CO₂ se banta hai.
• DAP (Diammonium phosphate) — N + P; SSP (Single superphosphate) — P; MOP (Muriate of potash = KCl) — K; ammonium sulphate, ammonium nitrate, CAN.
• जैव उर्वरक (Biofertilizers): Rhizobium (dalhan / legume ki jad ki granthiyon mein N₂ fix karta hai), Azotobacter, Anabaena / Nostoc (neel-harit shaival — dhaan ke khet), Mycorrhiza (phosphorus).
• Kaarbonik khaad (manure) mitti ki banaavat sudhaarti hai; rasayanik urvarak ka zyada upyog mitti aur paani pradooshit karta hai.

📌 9. बहुलक (Polymers) व प्लास्टिक (7 min read) — 2025 mein 6 sawal!

9.1 मूल बातें (Basics)

• बहुलक (Polymer) = chhoti ikaiyon (monomers / एकलक) ke baar-baar judne se bana bada anu. Jaise ethene → polythene.
• प्राकृतिक (Natural): starch, cellulose (ruee/lakdi), protein, DNA, natural rubber (polyisoprene), resham (silk — protein fibroin), oon (wool — protein keratin).
• अर्ध-संश्लेषित (Semi-synthetic): Rayon ("कृत्रिम रेशम / artificial silk") — lakdi ki lugdi (cellulose) se; vulcanised rubber.
• संश्लेषित (Synthetic): nylon, polyester, PVC, polythene, Teflon, Bakelite, acrylic.

9.2 Thermoplastic vs Thermosetting

9.3 प्रमुख बहुलक व उपयोग (Important Polymers)

• प्रत्यास्थलक (Elastomers): rubber jaise polymers — kheenchne par lambe hote hain aur chhodne par wapas apne aakar mein aa jaate hain (kamzor van der Waals bal). Natural rubber, neoprene, Buna-S.
• रेशे (Fibres): mazboot intermolecular bal (H-bond) → ucch tensile strength (nylon, polyester, silk).
• ऊन व रेशम = रेशेदार (fibrous) protein — lambe dhaage jaisi sanrachna, mazboot intermolecular bal, paani mein aghulansheel → reshe ban sakte hain. Albumin (ande ki safedi) = globular protein — gola, paani mein ghulansheel → reshe nahi banta.

9.4 जैव-निम्नीकरणीय (Biodegradable) व प्लास्टिक समस्या

• Zyadatar plastic अजैव-निम्नीकरणीय (non-biodegradable) — saalon tak nahi galta; jalane par zehreeli gases. 5R: Reduce, Reuse, Recycle, Recover, Refuse.
• Biodegradable polymers: PHBV, Nylon-2-Nylon-6, starch-based plastics.
• Starch plastic ki seema: starch paani/nami sokh leta hai aur iske yantrik gun (mechanical strength) kamzor hote hain.

📌 10. जैव-अणु व दैनिक जीवन में रसायन (Biomolecules & Chemistry in Daily Life) (7 min read)

10.1 कार्बोहाइड्रेट (Carbohydrates)

• Reducing sugar — Fehling's ghol (neela → laal Cu₂O avakshep) aur Tollens' reagent (silver mirror) ko reduce karti hai; iske liye mukt (free) aldehyde/ketone (anomeric carbon) chahiye.
• Do monosaccharides ग्लाइकोसिडिक बंध (glycosidic linkage) se judte hain. Sucrose mein glucose ka C1 aur fructose ka C2 — dono carbonyl carbon bond mein phans jaate hain (acetal/ketal linkage), isliye sucrose reducing nahi.

10.2 प्रोटीन, एंजाइम व न्यूक्लिक अम्ल

• Protein = amino acids ki chain, peptide bond se judi. Kul ~20 amino acids.
  • आवश्यक (Essential) amino acids — sharir khud nahi bana sakta, bhojan se lene padte hain (valine, leucine, lysine, tryptophan, phenylalanine...). Non-essential — sharir bana leta hai. (Vargikaran ka aadhar = sharir ki sanshleshan kshamta.)
  • Fibrous protein (keratin — baal/oon/naakhoon, collagen, fibroin — resham, myosin) — paani mein aghulansheel. Globular (albumin, insulin, haemoglobin, enzymes) — ghulansheel.
  • Sanrachna: primary (kram), secondary (α-helix, β-pleated sheet — H-bond se sthir), tertiary, quaternary. विकृतीकरण (Denaturation): garmi/acid se sanrachna bigadna — anda ubalna, doodh phatna.
• एंजाइम (Enzymes) = jaiv-utprerak (zyadatar protein); activation energy kam karte hain; bahut vishisht (specific). NCERT ke anusaar 6 classes — kis prakaar ki reaction utprerit karte hain, uske aadhar par: oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases.
  Examples: zymase (sharkara → ethanol, yeast), invertase (sucrose → glucose + fructose), diastase (starch → maltose), pepsin (protein).
• Nucleic acids: DNA (deoxyribose; A, T, G, C) va RNA (ribose; A, U, G, C) — details Biology page par.

10.3 दवाइयाँ व दैनिक रसायन (Medicines & Everyday Chemicals)

• Aspirin (salicylic acid ka acetyl roop) — acetyl group pet ki jalan (gastric irritation) kam karta hai jabki dard/soojan rodhi gun bane rehte hain; khoon patla karta hai (heart attack rokne mein). Salicylic acid khud pet ko zyada nuksan karta hai.

📌 11. उत्कृष्ट गैसें, हाइड्रोजन, वायु व रेडियोधर्मिता (Noble Gases, Hydrogen, Air & Radioactivity) (6 min read)

11.1 उत्कृष्ट / अक्रिय गैसें (Noble Gases — Group 18)

• Ye gases lagbhag nishkriya (inert) kyunki bahari kosh poora bhara hai (He mein 2, baaki mein 8 electrons).

11.2 हाइड्रोजन, जल व वायु (Hydrogen, Water & Air)

• Hydrogen — sabse halka tatva, brahmand mein sabse zyada. Isotopes: protium, deuterium, tritium.
• Jal ki kathorta (Hardness): asthaayi (temporary) — Ca/Mg ke bicarbonate → ubaalne se door; sthaayi (permanent) — Ca/Mg ke chloride/sulphate → washing soda ya ion-exchange se door.
• Vayu (Dry air): Nitrogen ~78%, Oxygen ~21%, Argon ~0.93%, CO₂ ~0.04%.
• Ozone (O₃) parat — stratosphere mein; suraj ki UV kirnon ko sokhti hai. CFCs (chlorofluorocarbons) — fridge/AC gas — ise nasht karti hain. Montreal Protocol (1987).
• Greenhouse gases: CO₂, methane (CH₄), N₂O, CFCs, jal-vaashp → global warming. Acid rain — SO₂ aur NOₓ.

11.3 रेडियोधर्मिता (Radioactivity)

• Khoj: Henri Becquerel (1896) — uranium mein. Marie & Pierre Curie — polonium aur radium khoja; Marie Curie — do alag vishayon (Physics 1903, Chemistry 1911) mein Nobel.
• SI unit: becquerel (Bq); purani unit: curie (Ci).

• अर्ध-आयु (Half-life): jitne samay mein aadhe radioactive nuclei vighatit ho jaayein.
• Carbon dating — C-14 (half-life ~5730 saal) se jeevashm/purani lakdi ki umr (W.F. Libby).
• Upyog: Cobalt-60 — cancer ilaaj; Iodine-131 — thyroid; Uranium-235 — nuclear reactor ka eedhan.