Is Organic Chemistry part of the EAPCET Chemistry syllabus?

Yes. Organic Chemistry is taught in Intermediate first year Chemistry, and the EAPCET Engineering syllabus is based on the Intermediate first- and second-year syllabus. Check the official notification each year for any changes.

How many Chemistry questions are there in EAPCET?

40 of the 160 questions in the Engineering paper are Chemistry, spread across 24 chapters.

What mistakes do students make in Organic Chemistry?

Applying the peroxide effect to HCl or HI — only HBr adds anti-Markovnikov in the presence of peroxide. Numbering a chain from the end nearest a substituent instead of the principal functional group — the principal group gets the lowest locant first. Assuming every compound with a C=C shows geometrical isomerism — each double-bond carbon must carry two different groups, so propene and 1-butene show none, while 2-butene does. Calling halogens meta-directing because they deactivate the ring — halogens are deactivating but ortho/para-directing.

EAPCET Chemistry · Intermediate first year

Organic Chemistry

Organic Chemistry covers the basic principles of organic chemistry — nomenclature, isomerism, electronic effects and reaction intermediates — together with hydrocarbons and their reactions.

Subject: Chemistry
Taught in: Intermediate first year
Chemistry in the paper: 40 of 160 questions

Key formulas and results

Carbocation stability: 3° > 2° > 1° > methyl
Markovnikov’s rule for addition of HX to alkenes; HBr with peroxide adds the other way (anti-Markovnikov)
Aromaticity requires $(4n + 2)$ π electrons in a planar ring (Hückel’s rule)
Ozonolysis cleaves C=C bonds into carbonyl compounds
Wurtz reaction joins alkyl halides with sodium; Friedel–Crafts adds alkyl or acyl groups to benzene
Tollens’ test: $\ce{RCHO + 2[Ag(NH3)2]+ + 3OH- -> RCOO- + 2Ag}$ (silver mirror) $\ce{+ 4NH3 + 2H2O}$
Fehling’s test: $\ce{RCHO + 2Cu^2+ + 5OH- -> RCOO- + Cu2O}$ (red precipitate) $\ce{+ 3H2O}$
Rosenmund reduction: $\ce{RCOCl + H2 ->[\text{Pd/BaSO}_4] RCHO + HCl}$
Stephen reduction: $\ce{RC#N} + \ce{SnCl2}/\text{HCl} \to$ imine, then $\ce{H3O+} \to \ce{RCHO}$
Clemmensen reduction (Zn–Hg/conc. HCl) and Wolff–Kishner reduction ( $\ce{NH2NH2}$ , then KOH/ethylene glycol) both convert $\mathord{>}\ce{C=O}$ into $\mathord{>}\ce{CH2}$
General formulae of open-chain hydrocarbons: alkanes $\ce{C_{n}H_{2n+2}}$ , alkenes $\ce{C_{n}H_{2n}}$ , alkynes $\ce{C_{n}H_{2n-2}}$
Number of structural (chain) isomers of alkanes: $\ce{C4H10} = 2$ , $\ce{C5H12} = 3$ , $\ce{C6H14} = 5$ , $\ce{C7H16} = 9$ , $\ce{C8H18} = 18$
Optical isomers for $n$ chiral carbons: unsymmetrical molecule $= 2^n$ (no meso form); symmetrical molecule with even $n$ $= 2^{n-1}$ optically active $+\ 2^{n/2 - 1}$ meso forms
Partial reduction of alkynes: $\ce{H2}$ with Lindlar catalyst ( $\ce{Pd/BaSO4}$ or $\ce{Pd/CaCO3}$ poisoned with quinoline) gives the cis-alkene; Na in liquid $\ce{NH3}$ (Birch reduction) gives the trans-alkene
Kolbe electrolysis: $\ce{2RCOONa + 2H2O -> R-R + 2CO2 + H2 + 2NaOH}$ (alkane and $\ce{CO2}$ at the anode, $\ce{H2}$ at the cathode)

What this chapter covers

IUPAC nomenclature
Isomerism
Inductive, resonance and hyperconjugation effects
Reaction intermediates
Alkanes, alkenes and alkynes
Aromatic hydrocarbons

How it is usually asked

IUPAC names
Reaction products
Stability order of intermediates
Counting isomers

Understanding Organic Chemistry

IUPAC naming follows fixed steps: find the longest chain containing the principal functional group, number it to give that group (and then multiple bonds and substituents) the lowest locants, and list substituents alphabetically. Isomers share a molecular formula but differ in structure (chain, position, functional group, metamerism) or in spatial arrangement (geometrical and optical isomerism). Geometrical isomerism needs restricted rotation and two different groups on each carbon of the double bond.

Electronic effects decide where and how reactions happen. The inductive effect is a permanent pull or push of electrons through sigma bonds; resonance spreads π electrons or lone pairs over several atoms; hyperconjugation involves C–H sigma bonds next to a carbocation, radical or double bond. These explain why carbocation and free-radical stability follow 3° > 2° > 1° > methyl, and why more substituted alkenes are more stable.

Alkenes undergo electrophilic addition: HX adds by Markovnikov’s rule, with H going to the carbon that already has more hydrogens. Only HBr, in the presence of a peroxide, adds the other way through a free-radical path. Alkynes add reagents twice, and terminal alkynes are weakly acidic. Benzene, with 6 π electrons, prefers substitution to addition; existing groups direct new ones to ortho/para or meta positions. EAPCET tests names, products, isomer counts and stability orders.

Worked example

EAPCET-style question

Propene reacts with HBr in the presence of benzoyl peroxide. The major product is:

(1)1-Bromopropane
(2)2-Bromopropane
(3)1,2-Dibromopropane
(4)Propane

Solution

With a peroxide present, HBr adds by a free-radical mechanism (the peroxide or Kharasch effect).
The peroxide generates Br•, which adds first to the C=C bond.
Br• adds to the terminal CH₂ so that the more stable secondary radical CH₃–ĊH–CH₂Br forms.
This radical takes H from HBr, giving CH₃CH₂CH₂Br (1-bromopropane) — anti-Markovnikov addition.
Without peroxide, the carbocation path gives 2-bromopropane instead.

Answer: 1-Bromopropane

Shortcuts and results to remember

Lucas test (conc. HCl + anhydrous ZnCl₂): 3° alcohols turn turbid at once, 2° in about 5 minutes, and 1° only on heating.
Victor Meyer test: 1° alcohols give a blood-red colour, 2° alcohols blue, and 3° alcohols stay colourless.
Tollens’ reagent oxidises both aliphatic and aromatic aldehydes but not ketones, while Fehling’s and Benedict’s solutions do not react with aromatic aldehydes such as benzaldehyde.
PCC stops at the aldehyde for 1° alcohols and gives ketones from 2° alcohols; hot copper at 573 K gives aldehyde from 1°, ketone from 2° and alkene from 3° alcohols.
NaBH₄ and LiAlH₄ reduce C=O but not an isolated C=C; Lindlar’s catalyst turns alkynes into cis-alkenes while Na in liquid NH₃ gives trans-alkenes; DIBAL-H reduces nitriles and esters to aldehydes.
Lucas test (conc. HCl + anhydrous ZnCl₂): 3° alcohols turn turbid at once, 2° alcohols in about 5 minutes, 1° alcohols show no turbidity at room temperature.

Common mistakes to avoid

Applying the peroxide effect to HCl or HI — only HBr adds anti-Markovnikov in the presence of peroxide.
Numbering a chain from the end nearest a substituent instead of the principal functional group — the principal group gets the lowest locant first.
Assuming every compound with a C=C shows geometrical isomerism — each double-bond carbon must carry two different groups, so propene and 1-butene show none, while 2-butene does.
Calling halogens meta-directing because they deactivate the ring — halogens are deactivating but ortho/para-directing.

How to prepare it

Named reactions are high-yield — keep a running list with one example of each.

Once the formulas feel familiar, test them the way the exam does: practise Organic Chemistry questions chapter-wise, then attempt a full previous year paper to see whether it holds up under a 3-hour timer.

Related Chemistry chapters

Environmental ChemistryIntermediate first year

See every chapter in the EAPCET Chemistry syllabus.

Practise Organic Chemistry chapter-wise

Chapter-wise quizzes show exactly which topics in this chapter you still get wrong — before a full paper does.

Frequently asked questions

Is Organic Chemistry part of the EAPCET Chemistry syllabus?: Yes. Organic Chemistry is taught in Intermediate first year Chemistry, and the EAPCET Engineering syllabus is based on the Intermediate first- and second-year syllabus. Check the official notification each year for any changes.
How should I prepare Organic Chemistry for EAPCET?: Named reactions are high-yield — keep a running list with one example of each.
How many Chemistry questions are there in EAPCET?: 40 of the 160 questions in the Engineering paper are Chemistry, spread across 24 chapters.
What mistakes do students make in Organic Chemistry?: Applying the peroxide effect to HCl or HI — only HBr adds anti-Markovnikov in the presence of peroxide. Numbering a chain from the end nearest a substituent instead of the principal functional group — the principal group gets the lowest locant first. Assuming every compound with a C=C shows geometrical isomerism — each double-bond carbon must carry two different groups, so propene and 1-butene show none, while 2-butene does. Calling halogens meta-directing because they deactivate the ring — halogens are deactivating but ortho/para-directing.