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Instruction
JAMB Chemistry 1993
JAMB (UTME)
Chemistry
1993
Q8351.Copper (II) tetraoxosulphate (VI) is widely used as a
AFertilizer
BFungicide
CDisinfectant
DPurifier
Correct Answer: B
Copper(II) sulphate (CuSO₄) is widely used as a fungicide (e.g., Bordeaux mixture).
JAMB (UTME)
Chemistry
1993
Q8352.Which of the following metals can be prepared in samples by the thermal decomposition of their trioxonitrate (V) salts?
ACopper and mercury
BSilver and copper
CMercury and silver
DMagnesium and mercury
Correct Answer: A
The trioxonitrate(V) salts of less reactive metals (Cu, Hg, Ag) decompose on heating to give the metal, NO₂, and O₂.
JAMB (UTME)
Chemistry
1993
Q8353.Which of the following compounds can exist as geometric isomers?
A2-methylbut-2-ene
BBut-2-ene
CBut-1-ene
DCH₂Cl₂
Correct Answer: B
Geometric (cis-trans) isomerism requires a C=C double bond with different groups attached to each carbon. But-2-ene (CH₃CH=CHCH₃) has this structure.
JAMB (UTME)
Chemistry
1993
Q8354.How many structural isomers can be written for the alkyl bromide C₄H₉Br?
A3
B4
C6
D8
Correct Answer: B
C₄H₉Br has four structural isomers: 1-bromobutane, 2-bromobutane, 1-bromo-2-methylpropane, and 2-bromo-2-methylpropane.
JAMB (UTME)
Chemistry
1993
Q8355.The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and
Achloromethane
Btetrachloromethane
Ctrichloromethane
Ddichloromethane
Correct Answer: B
The reaction between methane and excess chlorine in the presence of UV light proceeds to completion, forming tetrachloromethane (CCl₄) and hydrogen chloride (HCl).
JAMB (UTME)
Chemistry
1993
Q8356.How many grams of bromine will be required to completely react with 10 g of propyne?
A20 g
B40 g
C60 g
D80 g
Correct Answer: D
Propyne (C₃H₄) has a triple bond and can react with 2 moles of Br₂. Molar mass of propyne = 40 g/mol. Moles = 10/40 = 0.25 mol. Moles of Br₂ = 2 × 0.25 = 0.5 mol. Mass of Br₂ = 0.5 × 160 = 80 g.
JAMB (UTME)
Chemistry
1993
Q8357.Ethene when passed into concentrated H₂SO₄ is rapidly absorbed. The product is diluted with water and then warmed to produce
Aethanol
Bdiethyl ether
Cethanal
Ddiethyl sulphate
Correct Answer: A
Ethene reacts with concentrated H₂SO₄ to form ethyl hydrogen sulphate, which on hydrolysis gives ethanol.
JAMB (UTME)
Chemistry
1993
Q8358.One of the advantages of detergents over soap is that detergents
Aare easier to manufacture
Bfoam more than soap
Cform soluble salts with hard water
Dare able to deter germs more than soap
Correct Answer: C
Detergents do not form insoluble scum with hard water ions (Ca²⁺, Mg²⁺), so they work effectively in hard water, unlike soap.
JAMB (UTME)
Chemistry
1993
Q8359.CH₃CH₂CH₂CH₂Br + alc. KOH → X + KBr
Adehydration
Bdehydrohalogenation
Cneutralization
Da fission reaction
Correct Answer: B
The reaction is the removal of HBr (dehydrohalogenation) from an alkyl halide to form an alkene (butene).
JAMB (UTME)
Chemistry
1993
Q8360.A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water to be hygroscopic. This liquid is most likely to be
ACH₃CH₂CH₂CH₂OH
BCH₃CH₂OCH₂CH₃
CCH₃CH₂CHOHCH₃
DCH₂OHCHOHCH₂OH
Correct Answer: D
Glycerol (propane-1,2,3-triol, CH₂OHCHOHCH₂OH) is a viscous, non-toxic liquid with a high boiling point, miscible with water, and hygroscopic.
JAMB (UTME)
Chemistry
1993
Q8361.The compound CH₃CH₂CH(CH₃)CH₂Cl is known as
A1-chloro-2-methylbutane
B1-chloro-2-methylpropane
C2-chloromethylethane
D1-chloro-2,2-dimethylethane
Correct Answer: A
The longest chain has 4 carbons (butane) with a methyl group on carbon 2 and a chloro group on carbon 1. The correct name is 1-chloro-2-methylbutane.
JAMB (UTME)
Chemistry
1993
Q8362.Which of the following statements is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide?
A3 moles of NaOH are required for each mole of glyceride
B3 moles of glycerol are produced
Conly one mole of soap is formed
DConcentrated H₂SO₄ is essential for the completion of the reaction
Correct Answer: A
A glyceride (triglyceride) has three ester linkages. Complete hydrolysis (saponification) requires 3 moles of NaOH per mole of glyceride, producing 3 moles of soap and 1 mole of glycerol.
JAMB (UTME)
Chemistry
1993
Q8363.Which of the following are the products of the reaction between CH₃COOH and Cl₂ in sunlight?
AClCH₂COOH + HCl
BCH₃COCl + HCl
CCH₃COCl + HCl
DCH₃COCl + H₂O
Correct Answer: A
In the presence of sunlight, chlorine undergoes a substitution reaction with ethanoic acid, replacing a hydrogen on the alpha carbon to form chloroethanoic acid (ClCH₂COOH) and HCl.
Instruction
JAMB Chemistry 1994
JAMB (UTME)
Chemistry
1994
Q8364.A mixture of sand, ammonium chloride and sodium chloride is best separated by
Asublimation followed by addition of water and filtration
Bsublimation followed by addition of water and evaporation
Caddition of water followed by filtration and sublimation
Daddition of water followed by crystallization and sublimation
Correct Answer: A
Ammonium chloride sublimes on heating. The remaining mixture of sand and sodium chloride is treated with water; sodium chloride dissolves, sand does not. Filtration separates the sand from the salt solution.
JAMB (UTME)
Chemistry
1994
Q8365.A pure solid usually melts
Aover a wide range of temperature
Bover a narrow range of temperature
Cat a lower temperature than the impure one
Dat the same temperature as the impure one
Correct Answer: B
A pure solid has a sharp, definite melting point (narrow range). Impurities lower the melting point and cause it to melt over a wider range.
JAMB (UTME)
Chemistry
1994
Q8366.At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as
A25 cm³ of methane
B40 cm³ of hydrogen
C50 cm³ of ammonia
D100 cm³ of chlorine
Correct Answer: C
According to Avogadro's law, equal volumes of all gases at the same temperature and pressure contain the same number of molecules. Therefore, 50 cm³ of nitrogen contains the same number of molecules as 50 cm³ of ammonia.
JAMB (UTME)
Chemistry
1994
Q8367.8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22g of CH₃CH₂CH₃ occupy under the same condition?
A3.7 dm³
B11.2 dm³
C22.4 dm³
D33.6 dm³
Correct Answer: B
Molar mass of CH₄ = 16 g/mol. 8g = 0.5 mol. Molar mass of C₃H₈ (propane) = 44 g/mol. 22g = 0.5 mol. Equal moles of gas occupy equal volumes at s.t.p. So volume = 11.2 dm³.
JAMB (UTME)
Chemistry
1994
Q8368.To what temperature must a gas at 273 K be heated in order to double both its volume and pressure?
A298 K
B546 K
C819 K
D1092 K
Correct Answer: D
Using combined gas law: (P₁V₁)/T₁ = (P₂V₂)/T₂. P₂ = 2P₁, V₂ = 2V₁, T₁ = 273 K. T₂ = (P₂V₂T₁)/(P₁V₁) = (2P₁ × 2V₁ × 273)/(P₁V₁) = 4 × 273 = 1092 K.
JAMB (UTME)
Chemistry
1994
Q8369.For a gas, the relative molecular mass is equal to 2Y. What is Y?
AThe mass of the gas
BThe vapour density of the gas
CThe volume of the gas
DThe temperature of the gas
Correct Answer: B
Relative molecular mass = 2 × vapour density. Therefore, Y is the vapour density.
JAMB (UTME)
Chemistry
1994
Q8370.The densities of two gases, X and Y are 0.5 g dm⁻³ and 2.0 g dm⁻³ respectively. What is the rate of diffusion of X relative to Y?
A0.1
B0.5
C2.0
D4.0
Correct Answer: C
According to Graham's law, Rate_X/Rate_Y = √(d_Y/d_X) = √(2.0/0.5) = √4 = 2.0.
JAMB (UTME)
Chemistry
1994
Q8371.An increase in temperature causes an increase in the pressure of a gas because
Ait decreases the number of collisions between the molecules
Bthe molecules of the gas bombard the walls of the container more frequently
Cit increases the number of collisions between the molecules
Dit causes the molecules to combine
Correct Answer: B
Increasing temperature increases the average kinetic energy of gas molecules, causing them to move faster and bombard the walls of the container more frequently, thus increasing pressure.
JAMB (UTME)
Chemistry
1994
Q8372.The shape of ammonia molecule is
Atrigonal planar
Boctahedral
Csquare planar
Dtetrahedral
Correct Answer: A
Ammonia (NH₃) has a trigonal pyramidal shape due to the presence of a lone pair on the nitrogen atom. (The provided answer E is a typo; the correct answer is trigonal pyramidal).
JAMB (UTME)
Chemistry
1994
Q8373.The number of electrons in the valence shell of an element of atomic number 14 is
A1
B2
C3
D4
Correct Answer: D
Atomic number 14 is silicon (Si). Its electronic configuration is 1s² 2s² 2p⁶ 3s² 3p². It has 4 valence electrons.
JAMB (UTME)
Chemistry
1994
Q8374.Which of the following physical properties decreases down a group in the periodic table?
AAtomic radius
BIonic radius
CElectronegativity
DElectron affinity
Correct Answer: C
Electronegativity decreases down a group as the atomic radius increases and the nuclear charge is shielded by inner electrons.
JAMB (UTME)
Chemistry
1994
Q8375.The diagram above represents an atom of
AManganese
BHelium
CChlorine
DNeon
Correct Answer: D
The diagram shows 10 electrons in 2 shells (2, 8), which is the electronic configuration of neon (atomic number 10).
JAMB (UTME)
Chemistry
1994
Q8376.Elements X, Y and Z belong to groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ₃?
ABoth are electrovalent
BBoth are covalent
CXZ is electrovalent and YZ₃ is covalent
DXZ is covalent and YZ₃ is electrovalent
Correct Answer: C
X (Group I) is a metal, Z (Group VII) is a non-metal. XZ is ionic (electrovalent). Y (Group V) is a non-metal, so YZ₃ is covalent.
JAMB (UTME)
Chemistry
1994
Q8377.Which of the following atoms represents deuterium?
AProtons = 1, Neutrons = 0, Electrons = 0
BProtons = 1, Neutrons = 0, Electrons = 1
CProtons = 1, Neutrons = 1, Electrons = 1
DProtons = 1, Neutrons = 2, Electrons = 1
Correct Answer: C
Deuterium is an isotope of hydrogen with 1 proton, 1 neutron, and 1 electron.
JAMB (UTME)
Chemistry
1994
Q8378.The set-up above would be useful for determining the amount of
AOxygen in air
BWater vapour in air
CCO₂ in air
DArgon in air
Correct Answer: B
The setup uses anhydrous calcium chloride, which is a drying agent. It would be useful for determining the amount of water vapour in air.
JAMB (UTME)
Chemistry
1994
Q8379.A solid that absorbs water from the atmosphere and forms an aqueous solution is
Ahydrophilic
Befflorescent
Cdeliquescent
Dhygroscopic
Correct Answer: C
A deliquescent substance absorbs moisture from the atmosphere and dissolves in it to form a solution.
JAMB (UTME)
Chemistry
1994
Q8380.A major effect of oil pollution in coastal water is the
Adestruction of marine life
Bdesalination of water
Cincrease in the activity of the water
Ddetoxification of the water
Correct Answer: A
Oil pollution destroys marine life by coating the feathers of birds and the gills of fish, preventing them from breathing and insulating them.
JAMB (UTME)
Chemistry
1994
Q8381.Sodium chloride has no solubility product value because of its
Asaline nature
Bhigh solubility
Clow solubility
Dinsolubility
Correct Answer: B
Solubility product (Ksp) applies to sparingly soluble salts. Sodium chloride is highly soluble in water, so it is completely dissociated, and Ksp is not applicable.
JAMB (UTME)
Chemistry
1994
Q8382.The solubility in moles per dm³ of 20.2 g of potassium trioxonitrate (V) dissolved in 100 g of water at room temperature is
A0.10
B0.20
C1.00
D2.00
Correct Answer: D
Molar mass of KNO₃ = 39 + 14 + 48 = 101 g/mol. Moles = 20.2/101 = 0.2 mol. Volume of water = 100 g ≈ 100 cm³ = 0.1 dm³. Solubility = 0.2/0.1 = 2.00 mol dm⁻³.
JAMB (UTME)
Chemistry
1994
Q8383.A few drops of concentrated HCl are added to about 10 cm³ of a solution of pH 3.4. The pH of the resulting mixture is
Aless than 3.4
Bgreater than 3.4
Cunaltered
Dthe same as that of pure water
Correct Answer: A
Adding a strong acid (HCl) to a solution will increase the concentration of H⁺ ions, thus decreasing the pH. The pH will be less than 3.4.
JAMB (UTME)
Chemistry
1994
Q8384.Which of the following compounds is a base?
ACO₂
BCaO
CH₃PO₃
DCH₃COOH
Correct Answer: B
CaO (calcium oxide) is a basic oxide. It reacts with acids to form salts and water.
JAMB (UTME)
Chemistry
1994
Q8385.20 cm³ of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is
A2.50 g
B2.73 g
C3.28 g
D4.54 g
Correct Answer: C
Moles of ethanoic acid = 2.0 × 20/1000 = 0.04 mol. Moles of sodium ethanoate produced = 0.04 mol. Molar mass of CH₃COONa = 12 + 3 + 12 + 32 + 23 = 82 g/mol. Mass = 0.04 × 82 = 3.28 g.
JAMB (UTME)
Chemistry
1994
Q8386.What volume of oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?
A22.4 dm³
B11.2 dm³
C1.12 dm³
D0.560 dm³
Correct Answer: D
4OH⁻ → O₂ + 2H₂O + 4e⁻. 4F (4 × 96500 C) liberates 1 mole of O₂ (22.4 dm³). 9650 C liberates (9650/386000) × 22.4 = 0.560 dm³.
JAMB (UTME)
Chemistry
1994
Q8387.Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is
Amade both the anode and the cathode
Bmade the cathode
Cmade the anode
Ddissolved in the solution
Correct Answer: C
In electrorefining, the impure metal is made the anode. Pure copper is deposited at the cathode.
JAMB (UTME)
Chemistry
1994
Q8388.H⁻(s) + H₂O(l) → H₂(g) + OH⁻(aq). From the equation above, it can be inferred that the
Areaction is a double decomposition
Bhydride ion is a reducing agent
Chydride ion is an oxidizing agent
Dreaction is neutralization
Correct Answer: B
The hydride ion (H⁻) is oxidized to H₂ (0), so it acts as a reducing agent.
JAMB (UTME)
Chemistry
1994
Q8389.The ΔH for the reaction represented by the energy profile above is
A-100 kJ mol⁻¹
B+100 kJ mol⁻¹
C+50 kJ mol⁻¹
D-50 kJ mol⁻¹
Correct Answer: D
ΔH = Energy of products - Energy of reactants. From the diagram, reactants are at 100 kJ and products are at 50 kJ. ΔH = 50 - 100 = -50 kJ mol⁻¹.
JAMB (UTME)
Chemistry
1994
Q8390.An anhydride is an oxide of a non-metal
AWhich will not dissolve in water
Bwhose solution in water has pH greater than 7
Cwhose solution in water has a pH less than 7
Dwhose solution in water has a pH of 7
Correct Answer: C
Anhydrides of non-metals (acid anhydrides) dissolve in water to form acids, which have a pH less than 7.
JAMB (UTME)
Chemistry
1994
Q8391.MnO₄⁻(aq) + 8H⁺(aq) + 5Fe²⁺(aq) → Mn²⁺(aq) + 5Fe³⁺(aq) + 4H₂O(l). The oxidation number of manganese in the above reaction changes from
A+7 to +2
B+6 to +2
C+5 to +2
D+4 to +2
Correct Answer: A
In MnO₄⁻, Mn is +7. In Mn²⁺, it is +2.
JAMB (UTME)
Chemistry
1994
Q8392.In the diagram above, the activation energy is represented by
Ay - x
Bx
Cx - z
Dy
Correct Answer: A
Activation energy is the energy difference between the reactants (x) and the transition state (y). It is y - x.
JAMB (UTME)
Chemistry
1994
Q8393.Which of the following is TRUE of Le Chatelier's principle for an exothermic reaction?
AIncrease in temperature will cause an increase in equilibrium constant
BIncrease in temperature will cause a decrease in the equilibrium constant
CAddition of catalyst will cause an increase in the equilibrium constant
DAddition of catalyst will cause a decrease in the equilibrium constant
Correct Answer: B
For an exothermic reaction, increasing temperature shifts the equilibrium to the left (reverse reaction), decreasing the equilibrium constant.
JAMB (UTME)
Chemistry
1994
Q8394.Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?
AN₂O and steam
BNO₂ and ammonia
CN₂O₄ and NO₂
DNO and NO₂
Correct Answer: A
Ammonium trioxonitrate(V) (NH₄NO₃) decomposes on heating to give nitrous oxide (N₂O) and water (steam).
JAMB (UTME)
Chemistry
1994
Q8395.2HCl(aq) + CaCO₃(s) → CaCl₂(aq) + H₂O(l) + CO₂(g). From the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCl is added to it?
AL
BM
CN
DP
Correct Answer: B
The consumption of CaCO₃ will decrease over time as it reacts with HCl. Curve M represents a decreasing quantity.
JAMB (UTME)
Chemistry
1994
Q8396.In the diagram above, R is a mixture of
Apotassium tetraoxochlorate (VII) and concentrated H₂SO₄
Bpotassium tetraoxomanganate (VII) and concentrated HCl
Cmanganese (IV) oxide and concentrated HCl
Dmanganese (IV) oxide and concentrated HCl
Correct Answer: C
The setup is for the laboratory preparation of chlorine gas. It uses manganese(IV) oxide and concentrated hydrochloric acid.
JAMB (UTME)
Chemistry
1994
Q8397.Which of these metals CANNOT replace hydrogen from alkaline solutions?
AAluminium
BZinc
CTin
DIron
Correct Answer: D
Iron does not react with alkaline solutions to liberate hydrogen. Aluminium, zinc, and tin are amphoteric and can react with alkalis to produce hydrogen.
JAMB (UTME)
Chemistry
1994
Q8398.Clothes should be properly rinsed with water after bleaching because
Athe bleach decolorizes the clothes
Bchlorine reacts with fabrics during bleaching
Cthe clothes are sterilized during bleaching
Dhydrogen chloride solution is produced during bleaching
Correct Answer: D
Bleaching powder can leave behind traces of HCl, which can damage the fabric. Rinsing removes the acid.
JAMB (UTME)
Chemistry
1994
Q8399.Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?
ASodium trioxocarbonate (IV)
BSodium tetraoxosulphate
CSodium trioxosulphate (IV)
DSodium sulphide
Correct Answer: B
Barium chloride gives a white precipitate of barium sulphate (BaSO₄) with sodium tetraoxosulphate(VI) (Na₂SO₄). The precipitate is insoluble in dilute HCl.
JAMB (UTME)
Chemistry
1994
Q8400.SO₃ is NOT directly dissolved in water in the preparation of H₂SO₄ by the contact process because
Athe reaction between SO₃ and water is violently exothermic
Bacid is usually added to water and never water to acid
CSO₃ is an acid not dissolve in water readily
DSO₃ is an acid gas
Correct Answer: A
The reaction between SO₃ and water is highly exothermic and produces a mist of sulphuric acid, which is difficult to condense. Instead, SO₃ is dissolved in concentrated H₂SO₄ to form oleum.