MHT-CET Chemistry · Free notes
Basic Principles of Organic Chemistry — MHT-CET Chemistry
Basic Principles of Organic Chemistry is a Class 11 chapter and a light one on the MHT-CET paper — about one question a sitting, one in ten HARD. It is the grammar the organic chapters are written in: IUPAC names and the priority order of functional groups, the heterocycles by their heteroatom, the kinds of isomerism and how to spot a chiral carbon, and the electronic effects that rank carbocations and sort groups into donors and withdrawers. Three pages, ten cards, and every PYQ tagged. Read this before the Halogen Derivatives and Alcohols chapters, which assume all of it.
The handout has every subtopic, worked example, formula and trap with answers shown. The formula sheet is the chapter’s formulas and traps alone, on one page.
Subtopic notes
IUPAC Nomenclature, Functional Groups and Homologous Series
25 PYQsAn IUPAC name is built from the longest chain containing the principal functional group, numbered to give that group the lowest locant; which group is principal follows a fixed priority order, and a homologous series steps by one CH₂ (14 g mol⁻¹) at a time.
Isomerism and Stereochemistry
24 PYQsIsomers share a molecular formula: structural isomers differ in connectivity (chain, position, functional group, metamerism), stereoisomers in arrangement — and a carbon with four different groups makes a molecule chiral, giving a pair of non-superimposable mirror-image enantiomers.
Electronic Effects, Hybridisation, Intermediates and General Reactions
24 PYQsCarbon is sp³ with four single bonds, sp² at a double bond and sp at a triple bond; substituents push or pull electrons by induction and resonance, which is what ranks carbocations tertiary > secondary > primary > methyl and sorts groups into donors and withdrawers.
Formula & revision sheet
8 formulas · 2 reference tables · 10 gotchas across all subtopics — the exam-eve cheat-sheet
Formula & revision sheet
8 formulas · 2 reference tables · 10 gotchas across all subtopics — the exam-eve cheat-sheet
Formulas (2)
Reference tables (2)
Heterocyclic Compounds by Heteroatom6 rows
| Compound | Ring size | Heteroatom | Aromatic? |
|---|---|---|---|
| Pyrrole | 5 | N | Yes |
| Furan | 5 | O | Yes |
| Thiophene | 5 | S | Yes The only sulphur ring in the list. |
| Pyridine | 6 | N | Yes |
| Piperidine | 6 | N | No — saturated Piperidine has N, not S; it is the reduced form of pyridine. |
| Pyran | 6 | O | No Pyran contains NO nitrogen. |
Priority Order of Functional Groups11 rows
| Rank | Group | Suffix |
|---|---|---|
| 1 | −COOH | -oic acid |
| 2 | −SO₃H | -sulphonic acid Above esters and acid chlorides — the 2025 paper keys it over −COCl. |
| 3 | −COOR | -oate |
| 4 | −COCl | -oyl chloride |
| 5 | −CONH₂ | -amide |
| 6 | −CN | -nitrile |
| 7 | −CHO | -al |
| 8 | >C=O | -one Lowest of the carbonyl family. |
| 9 | −OH | -ol |
| 10 | −NH₂ | -amine |
| 11 | C=C, C≡C | -ene, -yne Never principal over a heteroatom group. |
Watch out for (4)
- Taking the difference as 12 or 2→ Homologous Series: One CH₂ at a Time
- Reading 'pyran' as a nitrogen ring→ Heterocyclic Compounds by Heteroatom
- Putting the acid chloride above the ester→ Priority Order of Functional Groups
- Numbering from the substituent-rich end→ Naming From a Structure, and Reading Bond-Line Formulas
Formulas (3)
Watch out for (3)
- Calling ether-versus-alcohol pairs metamers→ Structural Isomerism: Chain, Position, Functional, Metamerism
- Checking only the carbon that carries the halogen→ Chiral Carbons and Optical Activity
- Marking 'same chemical properties' as the false statement→ Enantiomers and the Fischer Projection
Formulas (3)
Watch out for (3)
- Hearing 'isopentane' as an alkene→ Hybridisation of Carbon and Counting From a Formula
- Calling −OH a withdrawer because oxygen is electronegative→ Inductive and Resonance Effects; Carbocation Stability
- Forgetting the extra carbon from CO₂→ Grignard Reagent, Dry Ice and the Clemmensen Reduction
PYQ weightage by concept
10 concepts · 73 PYQs — where the marks actually sit, so you know what to drill first
PYQ weightage by concept
10 concepts · 73 PYQs — where the marks actually sit, so you know what to drill first
| Concept | PYQs | Share |
|---|---|---|
| Heterocyclic Compounds by Heteroatom | 5 | 7% |
| Priority Order of Functional Groups | 5 | 7% |
| Naming From a Structure, and Reading Bond-Line Formulas | 5 | 7% |
| Homologous Series: One CH₂ at a Time | 3 | 4% |
| Concept | PYQs | Share |
|---|---|---|
| Enantiomers and the Fischer Projection | 4 | 5% |
| Chiral Carbons and Optical Activity | 3 | 4% |
| Structural Isomerism: Chain, Position, Functional, Metamerism | 2 | 3% |
| Concept | PYQs | Share |
|---|---|---|
| Hybridisation of Carbon and Counting From a Formula | 5 | 7% |
| Inductive and Resonance Effects; Carbocation Stability | 3 | 4% |
| Grignard Reagent, Dry Ice and the Clemmensen Reduction | 3 | 4% |
Test yourself on Basic Principles of Organic Chemistry
15 past MHT-CET questions from this chapter, timed at 14 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.