Filter by exam, subject and year then load questions instantly
Advertisement
post-utme2016chemistry
Q1. Which of the following compounds is used as a gaseous fuel?
ACH₃-CH₂-CHO₂-COOH
BCH₃-C≡CH
CCH₃-CH₂-CH₂-CH₃
DCH₂=CH-CH₃
Correct Answer: C
CH₃-CH₂-CH₂-CH₃ is butane, a saturated alkane widely used as a gaseous fuel in LPG (liquefied petroleum gas). Option B is propyne (an alkyne), D is propene (an alkene) — both are flammable but not common domestic gaseous fuels. Option A is not a real stable compound.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q2. Which of the following statements is correct about the periodic table?
AElements in the same group have the same number of electron shells
BThe non-metallic properties of the elements tend to decrease across each period
CElements in the same period have the same number of valence electrons
DThe valence electrons of the elements increase progressively across the period
Correct Answer: D
Across a period, the number of valence electrons increases progressively from left to right (e.g., Period 2: Li has 1, Be has 2, B has 3 … Ne has 8). Elements in the same group have the same number of valence electrons (not shells); elements in the same period have the same number of shells (not valence electrons); non-metallic properties increase across a period.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q3. The gas that is used for the treatment of cancer is
ANeon
BRadon
CXenon
DArgon
Correct Answer: B
Radon (Rn) is a radioactive noble gas used in radiotherapy for the treatment of cancer. Its radioactive decay produces alpha particles which can be used to irradiate and destroy cancerous tumours. The other noble gases (Ne, Xe, Ar) are not radioactive and have no such medical application.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q4. The relative atomic mass of a naturally occurring lithium consisting of 90% ⁷₃Li and 10% ⁶₃Li is
Butter is a solid emulsion — it is water droplets dispersed in a solid fat matrix. Milk is a liquid emulsion (fat droplets in water). Hair cream is a semi-solid emulsion (liquid in liquid). Cod-liver oil is a pure oil, not an emulsion. Therefore butter is the correct example of a solid emulsion.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q6. From the diagram above, an ideal gas can be represented by
AK
BM
CL
DN
Correct Answer: D
An ideal gas obeys Boyle's Law perfectly: PV = constant, meaning V is inversely proportional to P, giving a straight horizontal line when plotted as PV vs P. Curve N is the flat horizontal line in the diagram, representing a gas that shows no deviation from ideal behaviour across all pressures. Real gases (K, L, M) show deviations — dipping below or rising above the ideal line.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q7. The compounds CH₃CH₂CHO and CH₃COCH₃ can be distinguished from each other using
ADilute ammonia
BBenedict's solution
CTollen's reagent
DSodium hydroxide solution
Correct Answer: C
Tollen's reagent (ammoniacal silver nitrate) distinguishes aldehydes from ketones. CH₃CH₂CHO is an aldehyde and reduces Tollen's reagent to produce a silver mirror, while CH₃COCH₃ (a ketone) does not react. Benedict's solution also works with reducing sugars but Tollen's reagent is the classic test here.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q8. The compound CH₃-C(H)(OH)-COOH shown above exhibits
AGeometric isomerism
BPositional isomerism
CStructural isomerism
DOptical isomerism
Correct Answer: D
The compound shown is lactic acid (2-hydroxypropanoic acid). The central carbon atom is bonded to four different groups: CH₃, H, OH, and COOH. A carbon bonded to four different substituents is a chiral centre, making the compound optically active. It exhibits optical isomerism (enantiomers).
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q9. The curve depicts titration between
AStrong acid and strong base
BStrong acid and weak base
CWeak acid and weak base
DWeak acid and strong base
Correct Answer: B
The curve starts at a low pH (~3), indicating a strong acid. The equivalence point and the final pH (~5) are both in the acidic range, which is characteristic of a strong acid-weak base titration (the salt formed is acidic). A strong acid-strong base titration would end at pH 7, and a weak acid-strong base would end above pH 7.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q10. What is the concentration of a solution containing 2 g of NaOH in 100 cm³ of solution? [Na = 23, O = 16, H = 1]
A0.05 mol dm⁻³
B0.30 mol dm⁻³
C0.50 mol dm⁻³
D0.40 mol dm⁻³
Correct Answer: C
Molar mass of NaOH = 23 + 16 + 1 = 40 g mol⁻¹. Moles of NaOH = 2/40 = 0.05 mol. Volume = 100 cm³ = 0.1 dm³. Concentration = 0.05/0.1 = 0.50 mol dm⁻³.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q11. The process that requires the use of hard water in its operation is
ATanning
BBottling
CLaundry
DDyeing
Correct Answer: A
Tanning of leather requires hard water. The calcium and magnesium ions in hard water react with tannins to help harden and preserve animal hides. Hard water is undesirable for laundry (wastes soap), bottling, and dyeing processes.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q12. Ethanol is soluble in water due to the presence of a
ACarbonyl group
BHydroxyl group
CPhenyl group
DMethyl group
Correct Answer: B
Ethanol (C₂H₅OH) is soluble in water because of its hydroxyl group (-OH), which forms hydrogen bonds with water molecules. The -OH group is polar and interacts strongly with the polar water molecules, allowing ethanol to mix with water in all proportions.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q13. The compound produced when sodium peroxide is heated with excess sodium is
ANa₂CO₃
BNa₂O
CNaNO₂
DNaOH
Correct Answer: B
When sodium peroxide (Na₂O₂) is heated with excess sodium metal, the oxygen in the peroxide is reduced and sodium oxide (Na₂O) is formed: Na₂O₂ + 2Na → 2Na₂O. The excess sodium reduces the peroxide to the monoxide.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q14. In a neutralization reaction involving HCl and NaOH using litmus as indicator, the colour at the end point is
ABlue
BRed
COrange
DPurple
Correct Answer: D
At the end point of neutralization between HCl and NaOH, the solution is neutral (pH 7). Litmus turns red in acid, blue in alkali, and purple (its natural colour) in a neutral solution. Therefore the colour at the equivalence point is purple.
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q15. The monomer of nylon is
AHydroxybenzene
BHexanedioic acid
CBenzene-1,4-dicarboxylic acid
DEthane-1,2-diol
Correct Answer: B
Nylon-6,6 is formed by condensation polymerization of hexanedioic acid (adipic acid) and hexane-1,6-diamine. Hexanedioic acid is one of the two key monomers of nylon. Benzene-1,4-dicarboxylic acid and ethane-1,2-diol are monomers of Terylene (polyester).
Generating AI explanation...
AI Explanation
post-utme2016chemistry
Q16. An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contains is
A16
B15
C31
D46
Correct Answer: B
The atomic number of an element equals the number of protons in its nucleus. Since the atomic number is 15, the atom contains 15 protons. The number of neutrons = mass number − atomic number = 31 − 15 = 16.