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Playbook

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.

questions in the bank
45
tagged HARD
4%
subtopic(s)
6
worked examples
2

When you’ll see it

An allotrope-of-carbon property question, a name↔formula recall on a common organic compound, a functional-group identification, a soap/detergent classification, or a hydrocarbon-formula match.

How this chapter is tested

45 q in 10 years — NDA Chemistry's largest chapter. 2 HARD across the whole window, so it's mostly recall. The Allotropes subtopic alone is 15 q: diamond (sp³, hardest natural substance, electrical insulator), graphite (sp², layered, conducts electricity), fullerene (C₆₀ buckminsterfullerene), graphene (single graphite layer, strongest known material). Carbon's tetravalency + catenation explain why ~95% of all known compounds are organic.

Common Carbon Compounds (10 q) is name↔formula↔use recall — methane CH₄ (natural gas), ethanol C₂H₅OH (alcoholic drinks), formaldehyde HCHO (preservative), acetic acid CH₃COOH (vinegar), glucose C₆H₁₂O₆ (blood sugar). The /common-compounds reference page indexes these end-to-end.

Functional Groups (9 q) is the rule-application piece — given a structure, identify the FG: −OH alcohol, −CHO aldehyde, −COOH carboxylic acid, −NH₂ amine, −C=O ketone, −OR ether. Soaps + detergents (4 q): soap = Na/K salt of long-chain fatty acid; synthetic detergent = Na salt of long-chain sulphonic acid (work in hard water; soap doesn't).

The sub-skills

The rules and habits that decide whether you get a question right.

  • Allotrope property recall

    Diamond: sp³ tetrahedral, hardest, INSULATOR, transparent. Graphite: sp² layered, CONDUCTS electricity (delocalised e⁻), lubricant. Fullerene: cage (C₆₀). Graphene: single layer of graphite. Thermodynamically most stable: graphite (NOT diamond).

  • Common organic compound recall

    Methane CH₄, ethane C₂H₆, ethene C₂H₄, ethyne C₂H₂, ethanol C₂H₅OH, acetic acid CH₃COOH, methanol CH₃OH, formic acid HCOOH, formaldehyde HCHO, urea (NH₂)₂CO. Match name ↔ formula ↔ everyday use.

  • Functional-group identification

    −OH alcohol, −CHO aldehyde, −COOH carboxylic acid, >C=O ketone, −COO− ester, −NH₂ amine, −O− ether, −X halide. NDA tests FG recognition from a structural formula or from a property (acidic? sweet smell?).

  • Soap vs synthetic detergent

    Soap = sodium/potassium salt of fatty acid (R−COO⁻Na⁺). Synthetic detergent = sodium salt of long-chain sulphonic acid (R−SO₃⁻Na⁺) or alkyl sulfate (R−OSO₃⁻Na⁺). Detergents work in hard water; soaps don't (form scum with Ca²⁺/Mg²⁺).

2 worked examples from the bank

Real past-year questions illustrating the playbook. Click to reveal options + solution.

Example 1Carbon and Its CompoundsHARD
Which one of the following is NOT an example of organic compound?

[Q88 · Sep · 2023]

Example 2Carbon and Its CompoundsMODERATE
Consider the following statements: I. Soaps are sodium or potassium salts of long-chain carboxylic acids. II. Catenation and isomerism in carbon explain the large number of organic compounds. III. Carbon dioxide is acidic but carbon monoxide is a neutral molecule. Which are correct?

[Q88 · Apr · 2026]

Traps to expect

Distractor shapes specific to this chapter. The page-wide Traps section covers the bank-level patterns.

  • Diamond as 'electrical conductor'

    Diamond is an INSULATOR — sp³ carbons have no free electrons. The conductor in this family is GRAPHITE (sp², delocalised π electrons). Wrong option swaps them.

  • Thermodynamically stable form

    Despite diamond being harder + denser + more valuable, GRAPHITE is the thermodynamically more stable allotrope (ΔG_diamond→graphite < 0 at 25 °C, 1 atm). The trap option says 'diamond' because of intuitive 'strongest = most stable.'

  • Synthetic detergent = soap with extra steps

    Wrong. Soaps and synthetic detergents have DIFFERENT polar heads (carboxylate vs sulphonate/sulphate). The detergent class includes anionic, cationic, and non-ionic types — only some are 'soap-like.' Distractor lists all anionic compounds as synthetic detergents; some are not.

Drill every carbon and its compounds question

45 questions from the bank, scoped to 6 bundled subtopics.

Drill the 45 questions

Related playbooks

Often paired with this one — drill these next if you found the worked examples above tractable.