Organic Chemistry കാർബണിക രസതന്ത്രം
The chapter opens with rice, wheat, sugar and sugarcane. Food, medicines, plastic bottles, the cooking gas in an LPG cylinder and the petrol in a scooter are all made of carbon compounds. Carbon atoms share electrons and join each other into chains, branches and rings, so there are about ten times as many carbon compounds as compounds of all the other elements together. You will start with the simplest of them, the hydrocarbons, made of only carbon and hydrogen. You will sort them into alkanes, alkenes and alkynes, find their general formulas, give them their proper IUPAC names and meet ring compounds such as benzene and the naphthalene of moth balls. Then you will follow crude oil through the fractionating tower at a refinery like the one at Kochi and compare coal and natural gas (CNG, LNG). Last comes the fuel question of our time: global warming, and what all of us can do about it. This self-study guide starts from the basics and builds every structure with animations and virtual labs. It answers every textbook question and ends with a revision sheet and a model test.
The chapter in one picture
Parts 1–3: carbon's valency is 4, and carbon atoms join each other (catenation, കാറ്റിനേഷൻ) into straight chains, branched chains and rings (pages 1–8). Every carbon drawn here has exactly four bonds. Part 4: fractional distillation (അംശികസ്വേദനം) of crude oil (ക്രൂഡ് ഓയിൽ) in a fractionating tower (ഫ്രാക്ഷണേറ്റിങ് ടവർ), Fig 8.12 (page 9).
The chapter at a glance
🔗 Carbon compounds and hydrocarbons
- Organic compounds (ഓർഗാനിക് സംയുക്തങ്ങൾ): carbon compounds, except CO, CO₂, carbonates and bicarbonates · Berzelius, the vital force (ജീവശക്തി) and Wöhler's urea
- Hydrocarbons (ഹൈഡ്രോകാർബണുകൾ): only C and H · single, double and triple bonds
- Alkanes CₙH₂ₙ₊₂ (saturated) · alkenes CₙH₂ₙ and alkynes CₙH₂ₙ₋₂ (unsaturated)
- Homologous series (ഹോമലോഗസ് ശ്രേണി): neighbours differ by –CH₂–
- IUPAC names: word root (meth, eth, prop, but …) + ane / ene / yne
💍 Rings, fuels and the climate
- Ring compounds: alicyclic (cyclohexane C₆H₁₂) and aromatic (benzene C₆H₆, naphthalene C₁₀H₈) · catenation
- Petroleum (പെട്രോളിയം): a fossil fuel separated by fractional distillation into gases, petrol, kerosene, diesel … bitumen
- Coal (കൽക്കരി) from carbonisation: anthracite 94 % C, bituminous 83 %, lignite 67 %, peat 57 %
- Natural gas (പ്രകൃതിവാതകം): mainly methane · CNG and LNG
- Global warming (ആഗോളതാപനം): greenhouse gases CO₂, CH₄, N₂O, CFCs · what we can do
How to use this guide
🎬 Watch the animations
Carbon atoms share electrons, chains grow one –CH₂– at a time, a chain closes into a benzene ring and crude oil separates in a fractionating tower. Press Next ▶ or ▶▶ Auto play in the step-by-step boxes. Animations pause by themselves when you scroll away; click a lab to start its clock again.
🧪 Use the virtual labs
A structure builder (choose the carbons and the bonds, and the hydrogen atoms fill in by themselves), turning ball-and-stick models, a hydrogen-count pattern finder, a formula sorter, an IUPAC name machine, a ring gallery, a fractionating tower and a greenhouse-effect lab.
✍️ Try before you see
Every textbook table is a fill-in table with a check button, and every question hides its answer behind a button. Work it out in your notebook first. The “Check yourself” quizzes at the end of each page tell you at once whether you are right.
📖 Textbook words
Purple മലയാളം words are the exact terms used in your textbook (pages 153–174), so you can match this guide with your book and write answers in either language.
🔇 Quiet and offline
The pages make no sound and need no internet. Optional “Explore online” boxes link to checked websites (no videos); they open only if you click them. Every page is a single file, so the whole guide works on a computer or phone with no connection.
Learning path
Follow the pages in order. If you already know carbon's valency, single, double and triple bonds, and the difference between a structural and a molecular formula, you can skim pages 1–2. Still try their quizzes, because every page of the chapter draws structures.
Three scientists you will meet
Jöns Jacob Berzelius
1779–1848 · Swedish chemist- Gave the branch of chemistry about carbon compounds its name, organic chemistry (കാർബണിക രസതന്ത്രം).
- The name came from the belief that organic compounds could be made only by living things, with the help of a vital force (ജീവശക്തി).
- Read his side box on page 3 (textbook page 154).
Friedrich Wöhler
1800–1882 · German chemist- In 1828 he heated the inorganic substance ammonium cyanate and got urea, a compound found in urine: NH₄CNO → H₂N–CO–NH₂.
- That was the first blow to the vital-force theory. Kolbe made acetic acid (1845) and Berthelot made methane (1856) from inorganic substances, and the theory was dropped.
- The name “organic” stayed: today it simply means carbon compounds.
August Kekulé
1829–1896 · German chemist- Michael Faraday discovered benzene in 1825, but nobody knew how its six carbons and six hydrogens were joined.
- In 1865 Kekulé proposed a ring: a hexagon of carbon atoms with alternating single and double bonds.
- He said the idea came to him in a dream of a snake biting its own tail. Read the box on page 8 (textbook page 166).
Safety first
- Petrol, kerosene, diesel, turpentine and LPG are highly flammable. Never play with them, never store them near a flame or a stove, and never use petrol to light a fire.
- If you smell LPG at home (a smell is added to it on purpose), do not light anything or switch on lights or fans; close the regulator, open the doors and windows and call an adult.
- Naphthalene (moth balls, പാറ്റാഗുളിക) and benzene are toxic. Keep moth balls out of reach of small children, never chew or taste them, and wash your hands after touching them.
- Acetone (nail-polish remover) and other solvents give off vapours that catch fire easily; use them only with good air flow and away from flames.
- For the model-making activities use clay, beads, sticks or a model kit – never real chemicals.
Quick glossary (Malayalam ↔ English)
| Textbook term | English | Meaning |
|---|---|---|
| കാർബണിക രസതന്ത്രം | Organic chemistry | The study of carbon compounds |
| ഓർഗാനിക് സംയുക്തങ്ങൾ | Organic compounds | Compounds of carbon, except CO, CO₂, carbonates and bicarbonates |
| ജീവശക്തി | Vital force | The old (wrong) idea that organic compounds can be made only by living things |
| ഹൈഡ്രോകാർബണുകൾ | Hydrocarbons | Compounds made of only carbon and hydrogen |
| ഏകബന്ധനം · ദ്വിബന്ധനം · ത്രിബന്ധനം | Single bond · double bond · triple bond | One, two or three shared pairs of electrons between two atoms: C–C, C=C, C≡C |
| പൂരിത ഹൈഡ്രോകാർബണുകൾ | Saturated hydrocarbons | Hydrocarbons with only single bonds between carbon atoms (alkanes) |
| അപൂരിത ഹൈഡ്രോകാർബണുകൾ | Unsaturated hydrocarbons | Hydrocarbons with a double or triple bond between carbon atoms (alkenes, alkynes) |
| ഘടനാവാക്യം | Structural formula | A drawing that shows every atom and every bond |
| കണ്ടൻസ്ഡ് ഫോർമുല | Condensed formula | A short form showing each carbon with its hydrogens: CH₃–CH₂–CH₃ |
| തന്മാത്രാസൂത്രം | Molecular formula | The number of atoms of each element in one molecule: C₃H₈ |
| ബോൾ & സ്റ്റിക്ക് മാതൃക | Ball and stick model | A 3-D model with balls for atoms and sticks for bonds |
| ഓപ്പൺ ചെയിൻ | Open chain | Carbon atoms joined in a chain with two ends (not a ring) |
| ആൽക്കെയ്നുകൾ · ആൽക്കീനുകൾ · ആൽക്കൈനുകൾ | Alkanes · alkenes · alkynes | Open-chain hydrocarbons with only single bonds (CₙH₂ₙ₊₂) · at least one double bond (CₙH₂ₙ) · at least one triple bond (CₙH₂ₙ₋₂) |
| പൊതുവാക്യം | General formula | A formula with n that fits every member of a family, such as CₙH₂ₙ₊₂ |
| ഹോമലോഗസ് ശ്രേണി | Homologous series | A family of compounds with one general formula, neighbours differing by –CH₂– |
| നാമകരണം | Nomenclature (naming) | The system of naming compounds (IUPAC) |
| പദമൂലം | Word root | The part of a name that gives the number of carbons: meth 1, eth 2, prop 3, but 4 … |
| പ്രത്യയം · മുൻപ്രത്യയം | Suffix · prefix | An ending added to the root (-ane, -ene, -yne) · a beginning added in front (cyclo-) |
| വലയസംയുക്തങ്ങൾ | Cyclic (ring) compounds | Compounds whose carbon atoms are joined in a closed ring |
| ആലിസൈക്ലിക് സംയുക്തങ്ങൾ | Alicyclic compounds | Ring compounds that behave like open-chain alkanes and alkenes: cyclohexane |
| അരോമാറ്റിക് ഹൈഡ്രോകാർബണുകൾ | Aromatic hydrocarbons | Ring compounds with a characteristic smell: benzene, naphthalene |
| ബെൻസീൻ · നാഫ്തലീൻ | Benzene · naphthalene | C₆H₆, a six-carbon ring · C₁₀H₈, two benzene rings joined side by side |
| പാറ്റാഗുളിക | Moth ball | A white ball of naphthalene used to keep insects away from clothes |
| കാറ്റിനേഷൻ | Catenation | The ability of atoms of the same element to join each other; carbon has it most |
| പെട്രോളിയം · ക്രൂഡ് ഓയിൽ | Petroleum · crude oil | A natural mixture of hydrocarbons found deep between hard rocks |
| ഫോസിൽ ഇന്ധനം | Fossil fuel | A fuel formed from the remains of ancient living things: petroleum, coal, natural gas |
| അംശികസ്വേദനം | Fractional distillation | Separating a mixture of liquids by their different boiling points |
| ഫ്രാക്ഷണേറ്റിങ് ടവർ | Fractionating tower | The tall column at a refinery where crude oil is separated into fractions |
| കൽക്കരി · കാർബണൈസേഷൻ | Coal · carbonisation | A solid fossil fuel · plant remains slowly turning into carbon under high temperature and pressure without air |
| ആന്ത്രസൈറ്റ് · ബിറ്റുമിനസ് കോൾ · ലിഗ്നൈറ്റ് · പീറ്റ് | Anthracite · bituminous coal · lignite · peat | Kinds of coal, from the most carbon (94 %) to the least (57 %) |
| പ്രകൃതിവാതകം | Natural gas | A fossil fuel gas, mainly methane |
| സി.എൻ.ജി · എൽ.എൻ.ജി · എൽ.പി.ജി | CNG · LNG · LPG | Compressed natural gas · liquefied natural gas · liquefied petroleum gas (mainly butane) |
| ആഗോളതാപനം | Global warming | The rise in the average temperature of the Earth's surface and atmosphere |
| ഹരിതഗൃഹവാതകങ്ങൾ · ഹരിതഗൃഹപ്രഭാവം | Greenhouse gases · greenhouse effect | Gases such as CO₂, CH₄ and N₂O that trap heat · the warming of the Earth by these gases |
| ഇൻഫ്രാറെഡ് രശ്മികൾ | Infrared rays | Invisible heat rays given out by the warm surface of the Earth |
🌐 Explore online (optional)
Want to go further? The teaching pages end with a few checked websites (no videos), and page 12 has the full resources hub. They need the internet; the guide itself works offline. To begin, read about organic chemistry and catenation, or build and turn hydrocarbon molecules yourself in a simulation:
- 📄 Organic chemistry Wikipedia
The chemistry of carbon compounds. - 📄 Jöns Jacob Berzelius Wikipedia
Named the subject "organic chemistry". - 📄 Wöhler synthesis Wikipedia
1828: urea made from ammonium cyanate – the end of the vital-force theory. - 📄 Catenation Wikipedia
Why carbon can form long chains and rings. - 📄 Hydrocarbon Wikipedia
Compounds of only carbon and hydrogen. - 📄 Alkane Wikipedia
Saturated hydrocarbons CₙH₂ₙ₊₂. - 📄 Alkene Wikipedia
Hydrocarbons with a C=C double bond, CₙH₂ₙ. - 📄 Alkyne Wikipedia
Hydrocarbons with a C≡C triple bond, CₙH₂ₙ₋₂. - 📄 Homologous series Wikipedia
Neighbouring members differ by –CH₂–. - 🧪 Build a Molecule (PhET simulation) PhET, University of Colorado Boulder
Build methane, ethane, ethene and more from atoms. - 🧪 MolView MolView
Draw a structure and see it in 3D (try butane, benzene, cyclohexane).
Made for self-learning. Works offline – every page is a single file; only the optional "Explore online" links need the internet. Study material prepared by Claude for Madhu's family study folder, October 2026.