All 40 questions from the Joint Admissions and Matriculation Board (JAMB) Chemistry 2016 Objective paper, with the correct answer and a full explanation for each. Free, no signup needed.
Advertisement
1. The compound CH3-C(OH)-COOH exhibits a geometric isomerism (a) geometric isomerism (b) positional isomerism (c) structural isomerism (d) optical isomerism
The compound exhibits optical isomerism.
2. MnO4-(aq) + Y + 5Fe2+(aq) → Mn2+(aq) + 5Fe3+(aq) + 4H2O. In the equation above, is A. 10H+ B. 5H+ C. 8H+ D. 4H+
The balanced equation for the redox reaction between Fe2+ and MnO4- in acidic medium requires 8H+.
3. In an electrochemical cell, polarization is caused by A. oxygen B. hydrogenC. tetraoxosulphate VI acid D. chlorine
Polarization results from the accumulation of hydrogen. This can be rectified using a depolarizer such as manganese (IV) oxide, MnO2.
4. The condition required for corrosion to take place in the presence of A. oxygen and carbon (IV) oxide B. water and oxygen (IV) oxide C. water, carbon (IV) oxide and oxygen D. water and carbon (IV) oxide
The presence of water and oxygen (IV) oxide is the condition required for corrosion to take place.
5. The enzyme used in the hydrolysis of starch to dextrin and maltose is A. zymase B. sucrase C. amylase D. lactase
The enzyme used in the hydrolysis of starch to dextrin and maltose is amylase.
6. The products formed when propanol is heated over a copper catalyst in the absence of oxygen are A. CH3CH2CHO and H2 B. CH3CHO and CO2 C. CH3CH2COOH and H2 D. CH3COOH and CO2
The products formed when propanol is heated over a copper catalyst in the absence of oxygen are CH3CH2CHO and H2.
7. In the laboratory preparation of chlorine from concentrated hydrochloric acid in the presence of potassium tetraoxomanganate (VII) the gas produced is dried by passing it through A. concentrated tetraoxosulphate (VI) acid B. anhydrous calcium chloride C. calcium oxide D. sodium hydroxide
The usual drying agent for chlorine is concentrated tetraoxosulphate (VI) acid.
8. Which of the following compounds is used as a gaseous fuel? A. CH3-CH3-CHO2-COOH B. CH3-C≡CH-CH2-CH3 C. CH3-CH2-CH3 D. CH2-CH2-CH3(OH)
Gases like methane, ethane, propane and butane are usually employed as gaseous fuels. Utilgas (the gas we use at home) is normally propane or butane that has been sufficiently pressurized.
9. Cast iron is used in making A. chains and agricultural implements B. iron sheets and retort stand C. nails and iron rods D. stoves and cookers
Items which do not have to bear much strain such as stoves, cooker, pipes, radiators and Bunsen burner etc. are made of cast iron.
10. The monomer of nylon is A. hydroxybenzene B. hexanedioic acid C. benzene-1,4-dicarboxylic acid D. ethane-1,2-diols
The monomers of nylon-6,6 are hexane-1,6-diamine and hexanedioic acid.
11. The principle of column chromatography is based on the ability of the constituents to A. react with the solvent in the column B. react with each other in the column C. dissolve in each other in the column D. move at different speeds in the column
Chromatography is based on the ability of the constituents to move at different speeds in the column.
12. Ammonium chloride can be separated from its mixture with common salt by A. distillation B. evaporation C. decantation D. sublimation
Ammonium chloride can be separated from its mixture with common salt by sublimation. This is useful because ammonium chloride can sublime while common salt (NaCl) cannot.
13. H-C(H)(OH)-C(H)(H)-C(H)(H)-C(H)(Cl)H - The functional groups present in the compound above are A. alkene and halo-group B. hydroxyl and chloro-group C. alkene and chloro-group D. hydroxyl and halo-group
The functional groups present in the compound above are the hydroxyl group and chloro group.
14. The ability of carbon to form long chains is referred to as A. alkylation B. acylation C. catenation D. carbonation
Carbon has the ability to form long chain using its own atoms. This is known as catenation.
15. Alkanols have the general molecular formula A. CnH2n-2CHO B. CnH2n2COC C. CnH2n2OH D. CnH2n2OH
The general molecular formula for alkanols is CnH2n+1OH or ROH where R is the alkyl or aryl group.
16. The industrial preparation of hydrogen gas from water gas is referred to as A. Bosch process B. Contact process C. Haber process D. Bayer process
The industrial preparation of hydrogen gas from water gas is known as the Bosch process, in honour of Carl Bosch who first prepared hydrogen this way.
17. The relative atomic mass of a naturally occurring lithium consisting 90% ⁷Li and 10% ⁶Li is A. 6.2 B. 6.8 C. 7.1 D. 6.9
R.A.M = (Mass1×%1 + Mass2×%2)/100 = (7×90/100)+(6×10/100) = 6.3+0.6 = 6.9.
18. The colour of litmus in an alkaline medium is A. red B. yellow C. pink D. blue
Litmus has a red colour in acidic solutions, purple colour in neutral solutions and blue colour in alkaline solutions.
19. n monosaccharide ⇌ Polysaccharide in water. In the process above, P and Q respectively represent A. condensation and hydrolysis B. fermentation and condensation C. polymerization and hydrolysis D. polymerization and condensation
The conversion of a monosaccharide to a polysaccharide is by condensation while the reverse is by hydrolysis.
20. The compounds CH3CH2CHO and CH3COCH3 can be distinguished from each other using A. dilute ammonia B. Benedict's solution C. Tollen's reagent D. sodium hydroxide solution
CH3CH2CHO (an aldehyde) and CH3COCH3 (a ketone) can be distinguished using Tollen's reagent, since aldehydes are able to reduce mild oxidizing agents such as Fehling's and Tollen's reagents while ketones are not.
21. Which of the following statements is true about 2-methylpropane and butane? A. They have different number of carbon atoms B. They are members of the same homologous series C. They have the same boiling points D. They have the same chemical properties
2-methylpropane and butane are isomers. Since the two compounds differ only in the length of the continuous chain, their chemical properties are the same and they are members of the same homologous series.
22. N2O4(g) ⇌ 2NO2(g), ΔH = +ve. In the reaction above, an increase in temperature will A. increase the reactant production B. increase the value of the equilibrium constant C. shift the equilibrium to the left D. decrease the value of the equilibrium constant
Since the forward reaction is endothermic, the backward reaction will be exothermic. Thus, a decrease in temperature favours the backward reaction (equilibrium position shifts to the left); an increase in temperature favours the forward reaction and increases the equilibrium constant.
23. The process that requires the use of a solution of hard water in its operation is A. tanning B. bottling C. laundry D. dyeing
Although hard water usually gets in the way of many chemical processes (such as dyeing) because of the ions it contains, some processes are specially 'good-to-go' with hard water e.g. tannin.
24. What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O = 16, H = 1] A. 6.05 moldm-3 B. 0.30moldm-3 C. 0.50moldm-3 D. 0.40mol dm-3
Mass of NaOH = 2g; Molar mass of NaOH = 40gmol-1; Mole = 2g/40gmol-1 = 0.05mol; Volume of solution = 100cm3 = 0.1dm3; Concentration = 0.05mol/0.1dm3 = 0.5moldm-3.
25. The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is A. phosphorus-32 B. cobalt-60 C. carbon-14 D. iodine-131
Cobalt-60 is the radio isotope used in industrial radiography for the rapid checking of faults in welds and casting. The isotope is also used for destroying cancerous cells.
26. The compound produced when sodium is heated with excess sodium peroxide is A. Na2CO3 B. Na2O C. NaNO2 D. NaOH
Sodium oxide is produced when sodium peroxide (Na2O2) is heated with excess sodium metal: Na2O2 + 2Na → 2Na2O.
27. The pollutant that contributes to the depletion of the ozone layer is A. CFC(s) B. NO2 C. SO2 D. CO
Chlorofluorocarbons (CFC's) are the major culprits when it comes to the depletion of ozone layer.
28. Which of the following properties is not peculiar to matter? A. kinetic energy of particles increases from solid to gas B. Random motion of particles increases from gas to solid C. Orderliness of particles increases from gas to liquid D. Random motion of particles increases from liquid to gas
Random motion of particles increases from solid to gas and not the other way round.
29. In the diagram above, X is the A. enthalpy B. activated complex C. activation energy D. enthalpy change
In the diagram, X is the activation energy.
30. The diagram represents A. a spontaneous reaction B. an exothermic reaction C. a non-spontaneous reaction D. an endothermic reaction
The diagram (products at higher energy than reactants) represents an endothermic reaction.
31. Which of the following is not an alkali? A. Ca(OH)2 B. NH3 C. NaOH D. Al(OH)3
An alkali is a metallic hydroxide that is soluble in water. Examples of alkalis are NaOH and KOH. Ca(OH)2, Al(OH)3, Fe(OH)2, Fe(OH)3, NH4OH etc. are mere bases, not alkalis.
32. The curve depicts titration between (see pH graph). A. strong acid and strong base B. strong acid and weak base C. weak acid and weak base D. weak acid and strong base
Since the pH at the end point is less than 7, the curve represents the reaction between a weak acid and a strong base.
33. Which of the following statements is correct about the periodic table? A. Elements in the same group have the same number of electron shells B. The non-metallic properties of the elements tend to decrease across each period C. Elements in the same period have the same number of valence electrons D. The valence electrons of the elements iiyease progressively across the period
Elements in the same group have the same number of electrons at the outermost shell. The metallic character decreases across the period, while the non-metallic character does the opposite. Elements in the same period have the same number of electron shells. As we move from left to right across the periodic table, the valence electrons of the elements increase progressively.
34. The metal whose ore can be concentrated by passing it through a magnetic separator is A. Zn B. Sn C. Sb D. Ca
The ore of tin can be concentrated by passing it through a magnetic separator.
35. An example of an acidic oxide is A. NO B. CO C. SO2 D. CuO
SO3 is an acidic oxide. CuO is a basic oxide. NO & CO are neutral oxides.
36. What volume of 0.5MH2SO4 will exactly neutralize 20cm3 of 0.1M NaOH solution? A. 2.00cm3 B. 5.00cm3 C.6.8cm3 D. 8.3cm3
2NaOH + H2SO4 → Na2SO4 + 2H2O; Mole of NaOH = 0.020dm3×0.1M = 0.002mol; mole of H2SO4 required = 0.001mol; V = 0.001/0.5 = 0.002dm3 = 2cm3.
37. Diamond cannot be used in A. making bicycle chains B. abrasives C. cutting glass and metals D. dies for drawing wires
Due to its hardness, diamond can be used as an abrasive, for cutting glass and metals as dies for drawing wires. The use of diamond does not include making of bicycle chains.
38. Ethanol owes its solubility/miscibility in/with water to its possession of A. carbonyl group B. hydroxyl group C. phenyl group D. methyl group
Ethanol is soluble in water due to the presence of a hydroxyl group.
39. CH4(g) + Cl2(g) → CH3Cl(l) + HCl(g). The major factor that influences the rate of the reaction above is A. concentration B. catalyst C. temperature D. light
This depicts a substitution reaction between an alkane and a halogen. The reaction is photo-catalyzed.
40. The number of electronic shells contained in an atom with electron configuration 1s²2s²2p⁶3s²3p⁶4s² is A. 3 B. 2 C. 4 D. 5
1s2 2s2 2p6 3s2 3p6 4s2 = 20 electrons. The K, L, M, N shells structure will go as: 2, 8, 8, 2. Thus, the element has four shells.
Advertisement
…and/or go further with premium services and No Ads.