2012 JAMB CHEMISTRY PAST QUESTIONS AND ANSWERS Leave a Comment / Jamb Chemistry / By Jamb Tutor Report a question What’s wrong with this question? You cannot submit an empty report. Please add some details. 0% 0 votes, 0 avg Created by Jamb TutorJamb Chemistry 2012 JAMB CHEMISTRY PAST QUESTIONS AND ANSWERS 1 / 40 Category: Jamb Chemistry 2012 1. $$\text{Which Question Paper Type of Chemistry is given to you?}$$ a) $$\text{Type Green}$$ b) $$\text{Type Purple}$$ c) $$\text{Type Red}$$ d) $$\text{Type Yellow}$$ $$\text{The paper type ensures candidates’ questions are uniquely identified.}$$ 2 / 40 Category: Jamb Chemistry 2012 2. $$\text{Which of the following methods can be used to obtain pure water from a mixture of sand, water, and methanoic acid?}$$ a) $$\text{Neutralization with NaOH followed by filtration}$$ b) $$\text{Neutralization with NaOH followed by distillation}$$ c) $$\text{Fractional distillation}$$ d) $$\text{Filtration followed by distillation}$$ $$\text{Filtration separates sand; distillation separates water from methanoic acid.}$$ 3 / 40 Category: Jamb Chemistry 2012 3. $$\text{How many atoms are present in 6.0 g of magnesium?}$$ \text{[Mg = 24, } N_A = 6.02 \times 10^{23} \text{ mol}^{-1}]$$ a) $$1.20 \times 10^{22}$$ b) $$2.41 \times 10^{22}$$ c) $$1.51 \times 10^{23}$$ d) $$3.02 \times 10^{23}$$ $$\text{Moles of Mg} = \frac{6.0}{24}; \text{atoms} = \text{moles} \times N_A.}$$ 4 / 40 Category: Jamb Chemistry 2012 4. $$\text{50 cm}^3 \text{ of gas was collected over water at 10^{\circ}\text{C and 765 mmHg. Calculate the volume of gas at STP if the saturated vapor pressure of water at 10}^{\circ}\text{C is 5 mmHg.}$$ a) $$49.19 \text{ cm}^3$$ b) $$48.87 \text{ cm}^3$$ c) $$48.55 \text{ cm}^3$$ d) $$48.23 \text{ cm}^3$$ $$\text{Using } P_1V_1 = P_2V_2, \text{ adjust for water vapor pressure.}$$ 5 / 40 Category: Jamb Chemistry 2012 5. $$\text{An increase in pressure on gas at constant temperature results in}$$ a) $$\text{A decrease in the number of effective collisions}$$ b) $$\text{A decrease in volume}$$ c) $$\text{An increase in intermolecular distance}$$ d) $$\text{An increase in volume}$$ $$\text{By Boyle’s law, increasing pressure decreases volume.}$$ 6 / 40 Category: Jamb Chemistry 2012 6. $$2\text{H}_2(\text{g}) + \text{O}_2(\text{g}) \rightarrow 2\text{H}_2\text{O}(\text{g}) \text{. What volume of hydrogen is left when 300 cm}^3 \text{of oxygen reacts with 1000 cm}^3\text{ of hydrogen?}$$ a) $$200 \text{ cm}^3$$ b) $$400 \text{ cm}^3$$ c) $$600 \text{ cm}^3$$ d) $$700 \text{ cm}^3$$ $$\text{Ratio } H_2:O_2 = 2:1. 400 \text{ cm}^3 \text{ of H}_2 \text{ remains.}$$ 7 / 40 Category: Jamb Chemistry 2012 7. $$\text{Which of the following supports the particulate nature of matter? I. Evaporation, II. Sublimation, III. Diffusion, IV. Brownian motion.}$$ a) $$\text{I and III only}$$ b) $$\text{II and IV only}$$ c) $$\text{I, II, and III only}$$ d) $$\text{I, II, III, and IV}$$ $$\text{All listed phenomena confirm matter is made of particles.}$$ 8 / 40 Category: Jamb Chemistry 2012 8. $$\text{If X and Y have atomic numbers 11 and 17, what bond can they form?}$$ a) $$\text{Dative}$$ b) $$\text{Covalent}$$ c) $$\text{Ionic}$$ d) $$\text{Metallic}$$ $$\text{Na (11) and Cl (17) form ionic bonds by electron transfer.}$$ 9 / 40 Category: Jamb Chemistry 2012 9. $$\text{A hydrogen atom that has lost an electron contains}$$ a) $$\text{One proton only}$$ b) $$\text{One neutron only}$$ c) $$\text{One proton and one neutron}$$ d) $$\text{One proton, one electron, and one neutron}$$ $$\text{A hydrogen ion (H}^+\text{) is a single proton.}$$ 10 / 40 Category: Jamb Chemistry 2012 10. $$\text{The electronic configuration of Mg}^{2+} \text{ is}$$ a) $$1s^2 2s^2 2p^6 3s^2 3p^2$$ b) $$1s^2 2s^2 2p^6 3s^2$$ c) $$1s^2 2s^2 2p^6$$ d) $$1s^2 2s^2 2p^4$$ $$\text{Mg}^{2+} \text{ has lost 2 electrons, resulting in } 1s^2 2s^2 2p^6.}$$ 11 / 40 Category: Jamb Chemistry 2012 11. $$\text{Group VII elements are}$$ a) $$\text{Monoatomic}$$ b) $$\text{Good oxidizing agents}$$ c) $$\text{Highly electropositive}$$ d) $$\text{Electron donors}$$ $$\text{Halogens are strong oxidizing agents due to their high electronegativity and ability to gain electrons.}$$ 12 / 40 Category: Jamb Chemistry 2012 12. $$\text{Which of the following is used to study the arrangement of particles in crystal lattices?}$$ a) $$\text{Alpha-particles}$$ b) $$\text{Beta-particles}$$ c) $$\text{Gamma-rays}$$ d) $$\text{X-rays}$$ $$\text{X-rays are used in diffraction studies to analyze the arrangement of atoms in crystal lattices.}$$ 13 / 40 Category: Jamb Chemistry 2012 13. $$\text{Which of the following supports that air is a mixture?} \text{I. Varied composition, II. Physical separability, III. Presence of noble gases.}$$ a) $$\text{I and II only}$$ b) $$\text{II and III only}$$ c) $$\text{I and III only}$$ d) $$\text{I, II, and III}$$ $$\text{Air’s constituents can be separated physically, and its composition varies, proving it is a mixture.}$$ 14 / 40 Category: Jamb Chemistry 2012 14. $$\text{Chlorination of water for town supply is carried out to}$$ a) $$\text{Make the water colourless}$$ b) $$\text{Remove germs from the water}$$ c) $$\text{Make the water tasteful}$$ d) $$\text{Remove odour from the water}$$ $$\text{Chlorine disinfects water by killing harmful microorganisms, making it safe for consumption.}$$ 15 / 40 Category: Jamb Chemistry 2012 15. $$\text{The solubilities of different solutes in a given solvent can be compared by}$$ a) $$\text{Plotting their solubility curves on separate axes}$$ b) $$\text{Plotting their solubility curves on the same axes}$$ c) $$\text{Plotting some solubility curves on the x-axis and others on the y-axis}$$ d) $$\text{Plotting their solubility curves on the x-axis only}$$ $$\text{Plotting solubility curves on the same axes allows for direct comparison of solubilities.}$$ 16 / 40 Category: Jamb Chemistry 2012 16. $$\text{What mass of KCIO}_3 \text{ crystallizes out when a solution’s temperature drops from 45}^{\circ}\text{C to 20}^{\circ}\text{C? Solubilities: 1.5 mol dm}^{-3} \text{ to 0.5 mol dm}^{-3}. [K=39, Cl=35.5, O=16]$$ a) $$1.00 \text{ g}$$ b) $$10.00 \text{ g}$$ c) $$12.25 \text{ g}$$ d) $$122.50 \text{ g}$$ $$\text{Mass} = (1.5 – 0.5) \times \text{molar mass of } \text{KCIO}_3 = 122.5 \text{ g.}$$ 17 / 40 Category: Jamb Chemistry 2012 17. $$\text{Which of the following pollutants is associated with brain damage?}$$ a) $$\text{Carbon (II) oxide}$$ b) $$\text{Radioactive fallout}$$ c) $$\text{Biodegradable waste}$$ d) $$\text{Sulphur (IV) oxide}$$ $$\text{Radioactive fallout from nuclear waste or radiation can cause severe neurological damage.}$$ 18 / 40 Category: Jamb Chemistry 2012 18. $$\text{What number of moles of Cu}^{2+} \text{ are deposited by 360 coulombs of electricity? [F = 96500 C mol}^{-1}]$$ a) $$5.36 \times 10^{-4}$$ b) $$1.87 \times 10^{-3}$$ c) $$9.35 \times 10^{-4}$$ d) $$3.73 \times 10^{-3}$$ $$\text{Moles} = \frac{360}{96500 \times 2} = 1.87 \times 10^{-3}.}$$ 19 / 40 Category: Jamb Chemistry 2012 19. $$\text{A hydrogen atom that has lost an electron contains}$$ a) $$\text{One proton only}$$ b) $$\text{One neutron only}$$ c) $$\text{One proton and one neutron}$$ d) $$\text{One proton, one electron, and one neutron}$$ $$\text{A hydrogen ion (H}^+\text{) is a single proton.}$$ 20 / 40 Category: Jamb Chemistry 2012 20. $$\text{The electronic configuration of Mg}^{2+} \text{ is}$$ a) $$1s^2 2s^2 2p^6 3s^2 3p^2$$ b) $$1s^2 2s^2 2p^6 3s^2$$ c) $$1s^2 2s^2 2p^6$$ d) $$1s^2 2s^2 2p^4$$ $$\text{Mg}^{2+} \text{ has lost 2 electrons, resulting in } 1s^2 2s^2 2p^6.}$$ 21 / 40 Category: Jamb Chemistry 2012 21. $$\text{Group VII elements are}$$ a) $$\text{Monoatomic}$$ b) $$\text{Good oxidizing agents}$$ c) $$\text{Highly electropositive}$$ d) $$\text{Electron donors}$$ $$\text{Halogens are strong oxidizing agents due to their high electronegativity and ability to gain electrons.}$$ 22 / 40 Category: Jamb Chemistry 2012 22. $$\text{Which of the following is used to study the arrangement of particles in crystal lattices?}$$ a) $$\text{Alpha-particles}$$ b) $$\text{Beta-particles}$$ c) $$\text{Gamma-rays}$$ d) $$\text{X-rays}$$ $$\text{X-rays are used in diffraction studies to analyze the arrangement of atoms in crystal lattices.}$$ 23 / 40 Category: Jamb Chemistry 2012 23. $$\text{Which of the following supports that air is a mixture?} \text{I. Varied composition, II. Physical separability, III. Presence of noble gases.}$$ a) $$\text{I and II only}$$ b) $$\text{II and III only}$$ c) $$\text{I and III only}$$ d) $$\text{I, II, and III}$$ $$\text{Air’s constituents can be separated physically, and its composition varies, proving it is a mixture.}$$ 24 / 40 Category: Jamb Chemistry 2012 24. $$\text{Chlorination of water for town supply is carried out to}$$ a) $$\text{Make the water colourless}$$ b) $$\text{Remove germs from the water}$$ c) $$\text{Make the water tasteful}$$ d) $$\text{Remove odour from the water}$$ $$\text{Chlorine disinfects water by killing harmful microorganisms, making it safe for consumption.}$$ 25 / 40 Category: Jamb Chemistry 2012 25. $$\text{The solubilities of different solutes in a given solvent can be compared by}$$ a) $$\text{Plotting their solubility curves on separate axes}$$ b) $$\text{Plotting their solubility curves on the same axes}$$ c) $$\text{Plotting some solubility curves on the x-axis and others on the y-axis}$$ d) $$\text{Plotting their solubility curves on the x-axis only}$$ $$\text{Plotting solubility curves on the same axes allows for direct comparison of solubilities.}$$ 26 / 40 Category: Jamb Chemistry 2012 26. $$\text{What mass of KCIO}_3 \text{ crystallizes out when a solution’s temperature drops from 45}^{\circ}\text{C to 20}^{\circ}\text{C? Solubilities: 1.5 mol dm}^{-3} \text{ to 0.5 mol dm}^{-3}. [K=39, Cl=35.5, O=16]$$ a) $$1.00 \text{ g}$$ b) $$10.00 \text{ g}$$ c) $$12.25 \text{ g}$$ d) $$122.50 \text{ g}$$ $$\text{Mass} = (1.5 – 0.5) \times \text{molar mass of } \text{KCIO}_3 = 122.5 \text{ g.}$$ 27 / 40 Category: Jamb Chemistry 2012 27. $$\text{Which of the following pollutants is associated with brain damage?}$$ a) $$\text{Carbon (II) oxide}$$ b) $$\text{Radioactive fallout}$$ c) $$\text{Biodegradable waste}$$ d) $$\text{Sulphur (IV) oxide}$$ $$\text{Radioactive fallout from nuclear waste or radiation can cause severe neurological damage.}$$ 28 / 40 Category: Jamb Chemistry 2012 28. $$\text{What number of moles of Cu}^{2+} \text{ are deposited by 360 coulombs of electricity? [F = 96500 C mol}^{-1}]$$ a) $$5.36 \times 10^{-4}$$ b) $$1.87 \times 10^{-3}$$ c) $$9.35 \times 10^{-4}$$ d) $$3.73 \times 10^{-3}$$ $$\text{Moles} = \frac{360}{96500 \times 2} = 1.87 \times 10^{-3}.}$$ 29 / 40 Category: Jamb Chemistry 2012 29. $$\text{A hydrogen atom that has lost an electron contains}$$ a) $$\text{One proton only}$$ b) $$\text{One neutron only}$$ c) $$\text{One proton and one neutron}$$ d) $$\text{One proton, one electron, and one neutron}$$ $$\text{A hydrogen ion (H}^+\text{) is a single proton.}$$ 30 / 40 Category: Jamb Chemistry 2012 30. $$\text{The electronic configuration of Mg}^{2+} \text{ is}$$ a) $$1s^2 2s^2 2p^6 3s^2 3p^2$$ b) $$1s^2 2s^2 2p^6 3s^2$$ c) $$1s^2 2s^2 2p^6$$ d) $$1s^2 2s^2 2p^4$$ $$\text{Mg}^{2+} \text{ has lost 2 electrons, resulting in } 1s^2 2s^2 2p^6.}$$ 31 / 40 Category: Jamb Chemistry 2012 31. $$\text{The oxidation number of boron in NaBH}_4 \text{ is}$$ a) $$-3$$ b) $$-1$$ c) $$+1$$ d) $$+3$$ $$\text{Oxidation number of B is } +3 \text{ since H is } -1 \text{ and Na is } +1.}$$ 32 / 40 Category: Jamb Chemistry 2012 32. $$2\text{Na}_2\text{O}_2(\text{s}) + 2\text{H}_2\text{O}(\ell) \rightarrow 4\text{NaOH}(\text{aq}) + \text{O}_2(\text{g})$$ \text{. The substance oxidized is}$$ a) $$\text{Na}_2\text{O}_2(\text{s})$$ b) $$\text{NaOH}(\text{aq})$$ c) $$\text{H}_2\text{O}(\ell)$$ d) $$\text{O}_2(\text{g})$$ $$\text{Oxygen in Na}_2\text{O}_2 \text{ is oxidized from } -1 \text{ to } 0 \text{.}$$ 33 / 40 Category: Jamb Chemistry 2012 33. $$\text{A major factor in selecting a suitable method for preparing a simple salt is its}$$ a) $$\text{Crystalline form}$$ b) $$\text{Melting point}$$ c) $$\text{Reactivity with dilute acids}$$ d) $$\text{Solubility in water}$$ $$\text{Solubility determines whether precipitation, crystallization, or titration is appropriate.}$$ 34 / 40 Category: Jamb Chemistry 2012 34. $$\text{During a titration experiment, 0.05 moles of carbon (IV) oxide is liberated. What is the volume of gas liberated?}$$ a) $$22.40 \text{ dm}^3$$ b) $$11.20 \text{ dm}^3$$ c) $$2.24 \text{ dm}^3$$ d) $$1.12 \text{ dm}^3$$ $$\text{Volume} = \text{moles} \times 22.4 = 1.12 \text{ dm}^3 \text{ (STP conditions).}$$ 35 / 40 Category: Jamb Chemistry 2012 35. $$\text{An increase in entropy can best be illustrated by}$$ a) $$\text{Mixing of gases}$$ b) $$\text{Freezing of water}$$ c) $$\text{Condensation of vapour}$$ d) $$\text{Solidifying candle wax}$$ $$\text{Entropy increases in mixing gases due to greater randomness.}$$ 36 / 40 Category: Jamb Chemistry 2012 36. $$\text{The saponification of an alkanoate to produce soap and alkanol involves}$$ a) $$\text{Dehydration}$$ b) $$\text{Esterification}$$ c) $$\text{Hydrolysis}$$ d) $$\text{Oxidation}$$ $$\text{Saponification is the hydrolysis of esters in the presence of an alkali.}$$ 37 / 40 Category: Jamb Chemistry 2012 37. $$\text{Ethanol reacts with concentrated tetraoxosulphate (VI) acid at } 170^{\circ}\text{C to form}$$ a) $$\text{Ethanone}$$ b) $$\text{Ethene}$$ c) $$\text{Ethyne}$$ d) $$\text{Ethanal}$$ $$\text{Dehydration of ethanol produces ethene, an alkene.}$$ 38 / 40 Category: Jamb Chemistry 2012 38. $$\text{Which of the following compounds burns with a brick-red flame in a Bunsen burner?}$$ a) $$\text{LiCl}$$ b) $$\text{NaCl}$$ c) $$\text{CaCl}_2$$ d) $$\text{MgCl}_2$$ $$\text{Calcium compounds produce a characteristic brick-red flame.}$$ 39 / 40 Category: Jamb Chemistry 2012 39. $$\text{Geometric isomerism can exist in}$$ a) $$\text{Hex-3-ene}$$ b) $$\text{Hexane}$$ c) $$\text{Prop-1-ene}$$ d) $$\text{3-methyl but-1-ene}$$ $$\text{Hex-3-ene has restricted rotation around its double bond, allowing geometric isomers.}$$ 40 / 40 Category: Jamb Chemistry 2012 40. $$\text{An oxidation-reduction enzyme is}$$ a) $$\text{Amylase}$$ b) $$\text{Protease}$$ c) $$\text{Lipase}$$ d) $$\text{Dehydrogenase}$$ $$\text{Dehydrogenase facilitates redox reactions by transferring hydrogen atoms.}$$ Your score is The average score is 0% LinkedIn Facebook Twitter VKontakte 0% Restart quiz Anonymous feedback Send feedback
