The 2002 JAMB Chemistry paper evaluates fundamental concepts across general and organic chemistry, offering students a comprehensive review of core syllabus topics. Prominent themes recurring throughout this paper include organic nomenclature and functional group identification, stoichiometry alongside concentration calculations, and chemical equilibrium factors affecting reaction rates. Working through these questions provides a clear diagnostic check of your foundational knowledge. To get the most out of this practice page, make sure to review the detailed step-by-step explanations for every numerical problem rather than simply memorizing the final answer choices.
Topics in this paper
The IUPAC name of the compound CH₃CH(CH₃)CH₂CH₃ is
A student might mistakenly pick option B, C, or D by miscounting the carbon chain or misplacing the substituent position. To find the correct answer, identify the main carbon backbone: the longest chain has 4 carbons (butane); a methyl group is on carbon 2, so it’s 2-methylbutane. Common mistake: numbering from the wrong end of the carbon chain and misidentifying the locant number.
Which of the following is used as fuel in miners’ lamps?
A student could mistakenly choose option A, C, or D thinking another hydrocarbon or aldehyde possesses the high-luminosity combustion property required for industrial illumination. The correct answer is Ethyne because Ethyne (acetylene) burns with a bright flame, suitable for miners’ lamps. Common mistake: confusing the bright luminous flame of ethyne with the cleaner combustion of simpler alkanes like ethane.
Benzene reacts with hydrogen in the presence of a nickel catalyst at 180°C to form
One might mistakenly choose option A, B, or C by confusing an aromatic ring addition product with substituted aromatic derivatives like toluene or xylene. The correct answer is cyclohexane because benzene undergoes hydrogenation to form cyclohexane (C₆H₁₂). Common mistake: assuming adding hydrogen to an aromatic ring simply forms an alkyl-substituted ring rather than a fully saturated cyclic alkane.
Which gas hastens the ripening of fruits?
A student might mistakenly pick option B, C, or D thinking an alcohol or alkyne serves as the natural plant maturation hormone. The correct choice is Ethene because Ethene (ethylene) is a plant hormone that promotes fruit ripening. Common mistake: confusing ethene with its alkane counterpart ethane, which lacks plant hormone activity.
The final products of complete chlorination of methane in the presence of ultraviolet light are
A test-taker could mistakenly select option A, B, or D by assuming the halogenation process stops at an intermediate substitution stage. The correct choice is tetrachloromethane and HCl because, with excess chlorine, methane forms tetrachloromethane (CCl₄) and HCl. Common mistake: stopping the substitution at the trichloromethane stage when excess chlorine and UV light are present.
The correct order of increasing boiling points for C₃H₇OH, C₇H₁₆, and C₄H₁₀ is
A student might mistakenly select option A, C, or D by ignoring the powerful intermolecular forces present in alcohols compared to simple alkanes. The correct answer is C₄H₁₀ < C₇H₁₆ < C₃H₇OH because boiling points are: C₄H₁₀ (-0.5°C), C₇H₁₆ (98°C), C₃H₇OH (97°C, higher due to hydrogen bonding). Common mistake: assuming molecular mass alone dictates boiling point without accounting for hydrogen bonding in alcohols.
The haloalkane commonly used in dry cleaning is
One might mistakenly choose option A, B, or D thinking a simpler halomethane or anesthetic solvent is the standard industrial dry-cleaning agent. The correct answer is tetrachloroethene because Tetrachloroethene (C₂Cl₄) is a solvent used in dry cleaning. Common mistake: confusing trichloromethane with tetrachloroethene in industrial solvent applications.
A hydrocarbon Y treated with bromine water does not decolorize it. Y belongs to
A student might mistakenly select option A, B, or C believing that aromatic rings or unsaturated molecules fail to react with halogen solutions. The correct answer is alkanes because Alkanes do not react with bromine water; alkenes and alkynes decolorize it. Common mistake: assuming alkanes undergo addition reactions with bromine water similar to unsaturated hydrocarbons.
The compound historically used as an anaesthetic is
A student might pick option A, C, or D by confusing various halogenated methanes with the historical surgical agent. The correct answer is CHCl₃ because Chloroform (CHCl₃) was used as an anaesthetic. Common mistake: confusing carbon tetrachloride with chloroform regarding their historical medical applications.
A major use of alkanes is
A test-taker could mistakenly select option B, C, or D by associating saturated hydrocarbons with polymerization or catalytic addition processes. The correct option is as domestic and industrial fuel because Alkanes like methane and propane are widely used as fuels. Common mistake: confusing the chemical inertness of alkanes in industrial synthesis with their primary utility in combustion reactions.
The oxidation number of sulphur in H₂SO₄ is
One might mistakenly choose option A, B, or D by miscalculating the algebraic sum of oxidation states in the polyatomic ion. To find the correct answer, set up the equation: H (+1), O (-2); 2(+1) + S + 4(-2) = 0; S = +6. Common mistake: assigning an incorrect oxidation number to oxygen or hydrogen during the algebraic calculation.
Which of the following is a physical change?
A student might mistakenly choose option A, B, or D by confusing chemical transformations like combustion or oxidation with a phase change. The correct answer is Melting of ice because Melting of ice is reversible and involves no chemical change. Common mistake: failing to distinguish between temporary physical phase transitions and permanent chemical reactions.
The molarity of a solution containing 4.0 g of NaOH in 250 cm³ is [Na = 23, O = 16, H = 1]
A student could mistakenly select option A, C, or D by miscalculating the molar mass or volume conversion ratio. To determine the correct concentration: Molar mass NaOH = 40 g/mol; moles = 4/40 = 0.1 mol; volume = 0.25 L; M = 0.1/0.25 = 0.4 M. Common mistake: forgetting to convert the volume from cubic centimeters to liters when calculating molarity.
The gas responsible for acid rain is
A student might mistakenly pick option A, B, or D thinking another atmospheric pollutant creates strong bases rather than acidic precipitation. The correct answer is sulphur dioxide because Sulphur dioxide forms sulphurous and sulphuric acids in rain. Common mistake: confusing carbon monoxide toxicity with sulphur dioxide's role in forming acid rain.
The shape of a CH₄ molecule is
Students might mistakenly choose linear or trigonal planar by assuming fewer dimensions or miscounting electron domains. Looking at the molecule, the central carbon forms four distinct bonding pairs that repel each other maximally in three-dimensional space, producing a tetrahedral shape. Common mistake: Confusing the number of total bonds with the geometric arrangement.
Which of the following is an electrolyte?
Distractors like alcohol or sugar solution might seem plausible since they dissolve in water, but they do not form mobile charge carriers. Dissolving sodium chloride in water causes it to dissociate completely into separate ions, which allows the solution to conduct electricity. Common mistake: Assuming any dissolved substance automatically forms an electrolyte.
The main source of organic compounds is
One might pick coal or natural gas thinking of fossil fuels in general, but petroleum serves as the primary source of hydrocarbons. By evaluating the natural origin of these raw materials, petroleum is established as the main source of organic compounds. Common mistake: Confusing the primary source of hydrocarbons with secondary fossil fuel products.
The pH of a neutral solution at 25°C is
A student might incorrectly select 0 or 14 by picking the extremes of the pH scale rather than the neutral midpoint. At 25°C, the concentration of hydrogen ions equals the concentration of hydroxide ions at 10⁻⁷ M, and taking the negative logarithm yields a pH of 7. Common mistake: Confusing neutral solutions with acidic or basic extremes.
The gas that bleaches green leaves is
Carbon dioxide or sulphur dioxide might be chosen because they are common atmospheric gases associated with environmental effects. Chlorine acts directly by oxidizing chlorophyll, which causes the green leaves to undergo bleaching. Common mistake: Confusing acidic greenhouse gases with oxidizing bleaching agents.
The type of bond in ammonium chloride (NH₄Cl) is
A student could select ionic and covalent while missing the coordinate bond formed by the lone pair donation. Ammonium chloride features ionic interactions between the ammonium and chloride ions, covalent bonds holding the nitrogen and hydrogen atoms together, and a coordinate bond within the ammonium ion. Common mistake: Overlooking the dative or coordinate bond in complex ions.
Now practice in exam mode
You've studied the answers — now test yourself under real exam conditions with the timer running.
Start JAMB Chemistry 2002 QuizStudy JAMB Chemistry offline — no data needed
Get the JAMB app for Chemistry and every other subject — practice anywhere, even with no internet connection.