General Chemistry I — 2022 Past Questions

University of Ilorin CHM101: 135 questions.

Topics: Chemical equations and stoichiometry, Properties of gases, Redox reactions and introduction to electrochemistry, Elementary thermochemistry, Kinetic theory of matter, Atoms, elements, molecules, Chemical bonding and intermolecular forces, Valence, Modern electronic theory of atoms, Structure of solids, Radioactivity, Electronic configuration, Hybridisation and shapes of simple molecules, Acids, Bases and Salts

  1. Each of the following are endothermic reactions except?
    1. Boiling of water
    2. Ice melting
    3. Water condensation
    4. Water evaporation
  2. If the rate constant of a zero order reaction is 2.0×10⁻² and its concentration after 25 secs is 0.5M, calculate its initial concentration.
    1. 2
    2. 0.5
    3. 1
    4. 1.5
  3. A 25.7L of gas was kept at 690torr and 17°C, and had its pressure and temperature increased to 1.85atm and 345K respectively. Find its new volume.
    1. 13.1
    2. 14.1
    3. 15.1
    4. 12.9
  4. Sublimation is an example of ______ reaction and its change in enthalpy is ______.
    1. Endothermic, positive
    2. Exothermic, positive
    3. Endothermic, negative
    4. Exothermic, negative
  5. Isotones are?
    1. Atoms with same atomic number but different mass numbers
    2. Atoms with same neutrons but different protons and mass numbers
    3. Atoms with same protons but different neutrons
    4. Atoms with same mass number but different atomic numbers
  6. An atom with mass number 39 and atomic number 19 has how many neutrons?
    1. 20
    2. 10
    3. 19
    4. 39
  7. An element with atomic number 15 has what number of protons?
    1. 10
    2. 15
    3. 20
    4. 5
  8. The formula for dioxonitrate(III) ion is?
    1. NO₂⁻
    2. NO₃⁻
    3. N₂O₄²⁻
    4. NO₄³⁻
  9. Graph of log(A) against t with negative slope is of which order?
    1. Zero
    2. First
    3. Second
    4. Third
  10. Electron was discovered by?
    1. J.J. Thomson
    2. Rutherford
    3. Chadwick
    4. Mendeleev
  11. If the pressure and temperature of a liquid of 3 liter is doubled, what is the new volume?
    1. 6 L
    2. 3 L
    3. 1 L
    4. 9 L
  12. For a galvanic cell, the electromotive force is:
    1. E > 0
    2. E < 0
    3. E ≥ 0
    4. E ≤ 0
  13. A radioactive reaction is always known to be what order?
    1. Zero
    2. First
    3. Second
    4. Third
  14. A spontaneous electrochemical cell is called:
    1. Electrolytic
    2. Nernst
    3. Galvanic
    4. None of the above
  15. Which of these is not a standard electrode?
    1. Membrane
    2. Calomel
    3. Hydrogen
    4. Silver-silver chloride
  16. Which part is responsible for the volume of the atom?
    1. Extra-nuclear part (electron cloud)
    2. Protons
    3. Nucleus
    4. Neutrons
  17. J.J. Thomson's experiments led to the discovery of:
    1. The neutrality of atoms
    2. The stability of atoms
    3. Stability of nucleus
    4. All of the above
  18. 8g of CH₄ and 2g of H₂ gas at STP (760 mmHg, 298K). Total volume? (C=12, H=1, molar volume=22.4 dm³)
    1. 11.2 dm³
    2. 22.4 dm³
    3. 33.6 dm³
    4. 44.8 dm³
  19. Electromotive force is spontaneous when E is:
    1. > 0
    2. < 0
    3. = 0
    4. ≤ 0
  20. Which has the highest kinetic energy?
    1. Water (liquid)
    2. Sodium chloride crystal
    3. Benzene gas
    4. Aqueous solution
  21. Evaporation of liquid depends on: I. Surface area II. Temperature III. Nature of liquid
    1. I & II
    2. II only
    3. II & III
    4. I, II & III
  22. Which transition emits the strongest energy?
    1. n=3 → n=4
    2. n=4 → n=3
    3. n=2 → n=1
    4. n=1 → n=2
  23. When pressure and absolute temperature are doubled for 3L gas, new volume is:
    1. 6 L
    2. 3 L
    3. 12 L
    4. 0.5 L
  24. Which are examples of covalent bonds? I. Diamond II. Silica III. NaCl IV. Water
    1. I only
    2. I, II & III
    3. I, II & IV
    4. I & IV
  25. In K + Cu⁺(aq) → Cu + K⁺(aq), the cathode is:
    1. K
    2. Cu
    3. K⁺
    4. Cu⁺
  26. 290 mL gas at 17°C cools to -13°C. New volume?
    1. 260 mL
    2. 270 mL
    3. 280 mL
    4. 250 mL
  27. 20g FeCO₃ decomposes: FeCO₃ → Fe₂O₃ + 3CO₂. Volume of CO₂ at STP? (Fe=56, C=12, O=16, molar volume=22,400 cm³)
    1. 4,600 cm³
    2. 5,600 cm³
    3. 6,600 cm³
    4. 3,600 cm³
  28. When a crystalline solid is heated, what happens? I. Particle separation II. Melting III. Particle movement
    1. I & II
    2. III only
    3. I & III
    4. I, II & III
  29. If 2.41×10⁴ J of heat is required to raise the temperature of a substance of mass 105.0g by 125K, what is the specific heat capacity?
    1. 1.02×10⁻¹ Jg⁻¹K⁻¹
    2. 1.84 Jg⁻¹K⁻¹
    3. 9.18×10⁻⁴ Jg⁻¹K⁻¹
    4. 4.36×10⁻⁵ Jg⁻¹K⁻¹
  30. Vapor pressure is defined as:
    1. The pressure of a substance exerted on another during equilibrium
    2. The pressure of a vapor in contact with its liquid/solid phase
    3. The total pressure of a gas mixture
    4. Atmospheric pressure at boiling point
  31. The formula for trioxoborate(III) acid is:
    1. H₃BO₃
    2. H₂BO₃
    3. HBO₃
    4. H₃BO₄
  32. Find the percentage of water in KAl(SO₄)₂·12H₂O:
    1. 41.1%
    2. 35.2%
    3. 48.7%
    4. 52.9%
  33. If 1 mole O uses 0.4 mole P, what is the empirical formula?
    1. P₂O₅
    2. PO₂
    3. PO
    4. PO₄
  34. When a crystalline solid is cut, it shows:
    1. I only (clean cleavage)
    2. II & III (isotropic with directional properties)
    3. I & III (cleavage and anisotropic properties)
    4. I, II & III
  35. How many types of nodes exist in atomic orbitals?
    1. 4
    2. 2
    3. 1
    4. 3
  36. Which has the highest density?
    1. Glass
    2. Water
    3. Air
    4. Ethanol
  37. What is the molality of 15g Al(OH)₃ in 90g solution?
    1. 0.69 m
    2. 2.14 m
    3. 1.13 m
    4. 3.52 m
  38. An element with valency 4 forms chloride and oxide. What is their ratio?
    1. 2:1
    2. 4:2
    3. 2:4
    4. 1:4
  39. Which reaction type has only one reactant?
    1. First order reaction
    2. Second order reaction
    3. Unimolecular reaction
    4. Bimolecular reaction
  40. 12g CH₄ and 2g H₂O at STP. Total volume?
    1. 19.27 L
    2. 22.4 L
    3. 16.8 L
    4. 11.2 L
  41. Reference electrode cell potential is:
    1. -3.4 V
    2. 0.76 V
    3. -0.76 V
    4. 0.00 V
  42. 290mL gas at 17°C cools to -13°C at constant pressure. New volume?
    1. 260 mL
    2. 270 mL
    3. 280 mL
    4. 250 mL
  43. Molarity of 2% w/v KOH solution:
    1. 0.45 M
    2. 0.35 M
    3. 0.2 M
    4. 0.78 M
  44. For zero-order reaction 3A → B + C, doubling [A] affects rate by:
    1. Doubling rate
    2. Halving rate
    3. No change in rate
    4. Quadrupling rate
  45. If 1.96g of Na₂CO₃·xH₂O is heated and 0.53g remains after releasing water of crystallization, find x.
    1. 7
    2. 10
    3. 5
    4. 3
  46. Which process has the highest enthalpy for 10g H₂?
    1. Vaporization
    2. Melting
    3. Fusion
    4. Freezing
  47. Which ion has the fewest unpaired d electrons?
    1. Fe³⁺ (3d⁵)
    2. Mn²⁺ (3d⁵)
    3. Co²⁺ (3d⁷)
    4. Co³⁺ (3d⁶)
  48. Which is NOT matter?
    1. Thought
    2. Fire
    3. Air
    4. All are matter
  49. 275 mL gas at 40°C cools to -15°C. New volume?
    1. 226 mL
    2. 250 mL
    3. 200 mL
    4. 275 mL
  50. Photoelectron emission depends on:
    1. Frequency
    2. Intensity
    3. Wavelength
    4. Work function
  51. 8g CH₄ + 2g H₂ at 460 mmHg and 273K. Volume?
    1. 28.0 L
    2. 22.4 L
    3. 33.6 L
    4. 11.2 L
  52. Incorrect statement about zero-order reactions:
    1. Rate constant unit is s⁻¹
    2. Rate is independent of [A]
    3. Half-life depends on initial [A]
    4. Graph of [A] vs t is linear
  53. Highest endothermic ΔH for 10g substance?
    1. Vaporization
    2. Sublimation
    3. Melting
    4. Deposition
  54. Compound of X (valency 3) and Y (valency 5):
    1. X₃Y₅
    2. X₅Y₃
    3. X₈Y₅
    4. X₃Y₈
  55. Chemical reactions occur when:
    1. Effective collisions happen
    2. Particles physically mix
    3. Temperature increases
    4. Pressure decreases
  56. Given E°(Zn²⁺/Zn) = -0.25V, E°(Cu²⁺/Cu) = +0.34V, the cathode is:
    1. Zn
    2. Cu
    3. H₂
    4. Pt
  57. Ratio of Ca₃P₂ to Ca atoms:
    1. 1:3
    2. 2:6
    3. 1:2
    4. 4:5
  58. Pressure of 8g CH₄ + 2g H₂ in 10L at 273K:
    1. 2.80 atm
    2. 1.12 atm
    3. 3.36 atm
    4. 0.56 atm
  59. Lowest ΔH value?
    1. Heat of vaporization
    2. Heat of fusion
    3. Heat of condensation
    4. Heat of sublimation
  60. Bond-breaking ΔH is:
    1. Positive
    2. Negative
    3. Zero
    4. Variable
  61. Non-spontaneous reaction cell:
    1. Galvanic cell
    2. Electrochemical cell
    3. Electrolytic cell
    4. Voltaic cell
  62. Factors affecting evaporation:
    1. Surface area only
    2. Temperature and nature of liquid
    3. All factors (I, II, III)
    4. Pressure only
  63. Energy measure at constant T and V:
    1. Entropy (S)
    2. Enthalpy (H)
    3. Internal energy (U)
    4. Work (w)
  64. Cell using electricity for spontaneous process:
    1. Electrolytic cell
    2. Electrochemical cell
    3. Electrolysis
    4. Voltaic cell
  65. Highest density material:
    1. Glass
    2. Diethyl ether
    3. Water
    4. Aluminum
  66. Highest kinetic energy system:
    1. NaCl crystal
    2. Liquid water
    3. Butane gas
    4. Kerosene liquid
  67. If element M forms MCl₂, what is the formula of its nitrate?
    1. MNO₃
    2. M(NO₃)₂
    3. M₂NO₃
    4. M(NO₃)₃
  68. Calculate the half-life (t½) if decay constant (λ) is 0.00625 s⁻¹.
    1. 96 s
    2. 110 s
    3. 50 s
    4. 200 s
  69. For C₃H₈ + xO₂ → 3CO₂ + yH₂O, find y:x ratio.
    1. 5:4
    2. 4:5
    3. 1:3
    4. 2:4
  70. Rate law for zero-order reaction 2A + B → C is:
    1. Rate = k[A]²[B]
    2. Rate = k[A][B]⁰
    3. Rate = k[A]²[B]⁰
    4. Rate = k[A]⁰[B]⁰
  71. Mass of a neutron is approximately:
    1. 1.672 × 10⁻²⁴ g
    2. 1.675 × 10⁻²⁴ g
    3. 9.1 × 10⁻²⁸ g
    4. 1.6 × 10⁻¹⁹ g
  72. Mass of 2.3 × 10²² CO₃²⁻ ions:
    1. 2.28 g
    2. 1.14 g
    3. 3.42 g
    4. 4.56 g
  73. Unit of reaction rate is:
    1. mol L⁻¹ s⁻¹
    2. mol s⁻¹
    3. L mol⁻¹ s⁻¹
    4. s⁻¹
  74. Standard EMF of Pb²⁺/Pb (-0.13V) and Au³⁺/Au (+1.50V) cell:
    1. 1.63 V
    2. 1.37 V
    3. 0.76 V
    4. 2.50 V
  75. Half-life of drug with k = 1.5 × 10⁻³ s⁻¹ at pH 7.0:
    1. 462 s
    2. 300 s
    3. 600 s
    4. 150 s
  76. IUPAC name for [Fe(OH)₄]⁻:
    1. Tetrahydroxoferrate(III)
    2. Ferrate(III) tetrahydroxide
    3. Iron(III) hydroxide ion
    4. Hydroxoferrate(III)
  77. Molar mass of X in XO₂ (4g, 1.40 L at STP):
    1. 32 g/mol (S)
    2. 44 g/mol (CO₂)
    3. 16 g/mol (O)
    4. 64 g/mol (SO₂)
  78. IUPAC formula for sodium iron(III) tetraoxosulfate(VI):
    1. NaFe(SO₄)₂
    2. Na₃[Fe(SO₄)₃]
    3. Na[Fe(SO₄)₂]
    4. Na₂Fe(SO₄)₃
  79. Ratio of H₂O to O₂ in C₇H₆O₂ + O₂ → CO + H₂O (unbalanced):
    1. 5:5
    2. 6:15
    3. 5:20
    4. None
  80. Speed of chemical reactions:
    1. Constant regardless of temperature
    2. Unaffected by solid surface area
    3. Always rapid for gases due to high KE
    4. Extremely rapid for aqueous ions (no bonds to break)
  81. Relationship between intermolecular forces and vapor pressure:
    1. Directly proportional
    2. Inversely proportional
    3. No relationship
    4. Exponential
  82. For element M with valency 4, what is the ratio of chlorine to oxygen valency when combined with M?
    1. 1:2
    2. 2:4
    3. 0:1
    4. 4:2
  83. If first ionization energy of H is E, then ionization energy of He⁺ is:
    1. 2E
    2. E
    3. 4E
    4. 0.5E
  84. Identify element M in M(NO₃)₂·4H₂O given 0.59g hydrate → 0.41g anhydrous:
    1. Mg (24)
    2. Na (23)
    3. Ca (40)
    4. Zn (65)
  85. Arrange in increasing volume at STP:
    1. 2.0g CO₂ (0.045 mol)
    2. 0.3g H₂ (0.15 mol)
    3. 1.23g N₂ (0.044 mol)
    4. 0.1g H₂O (liquid)
  86. Gas volume at 1.85 atm and 72°C if initially 25.8 L at 690 torr and 17°C:
    1. 36.8 L
    2. 15.1 L
    3. 51.55 L
    4. None
  87. Correct statement about temperature increase in reactions:
    1. Increases activation energy
    2. Increases reaction rate
    3. Increases reactant concentration
    4. II and III
  88. Which uses electric flow only?
    1. Electrochemistry
    2. Galvanic cell
    3. Electrolytic cell
    4. None
  89. Which has the least atoms? [N=14, O=16, C=12, H=1]
    1. 5.2g N₂ (0.185 mol, 0.37 mol atoms)
    2. 2.8g O₃ (0.058 mol, 0.175 mol atoms)
    3. 7g C₂ (0.29 mol, 0.58 mol atoms)
    4. 1g H₂ (0.5 mol, 1 mol atoms)
  90. Volume of 1 mol gas at STP:
    1. 22400 m³
    2. 22.4 cm³
    3. 22.4 dm³ (0.0224 m³)
    4. None
  91. For rate law k[A]²[B], the reaction order is:
    1. 1st order A, 3rd overall
    2. 2nd order B, 3rd overall
    3. 2nd order A, 3rd overall
    4. 1st order B, 2nd overall
  92. Which is NOT matter?
    1. Fire (plasma)
    2. Thought
    3. Air (gas)
    4. All are matter
  93. Graph of ln[A] vs t with slope -k indicates:
    1. 1st order
    2. 2nd order
    3. 3rd order
    4. Zero order
  94. A given mass of gas occupies 25.8L at 690torr and 17°C. Calculate volume at 1.85atm and 72°C
    1. 36.8L
    2. 15.1L
    3. 51.55L
    4. 52L
  95. A proton is a
    1. Ionized hydrogen molecule
    2. Ionized hydrogen atom
    3. Alpha particle
    4. Deuterium
  96. Mixture of 8g O₂ and 4g H₂ at STP. Total pressure?
    1. 1.5atm
    2. 2.25atm
    3. 3.0atm
    4. 0.75atm
  97. First-order reaction: time for [A] to drop from 0.100M to 0.050M is 156s. Time for 0.050M to 0.025M?
    1. 165s
    2. 76s
    3. 156s
    4. 98s
  98. NH₄NO₂ decomposition (k=0.0198s⁻¹ at 680°C). Time for [0.57M]→[0.013M]?
    1. 191s
    2. 183s
    3. 57s
    4. 83s
  99. A catalyst functions by:
    1. Lowering reactant energy
    2. Lowering product energy
    3. Decreasing reverse reaction rate
    4. Providing lower Eₐ path
  100. Reaction rate doubles when [reactant] doubles. Reaction order is:
    1. Zero
    2. First
    3. Second
    4. Third

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