EST2 HS CHEMISTRY
๐ ULTIMATE MOCK EXAM
120 Very Hard Questions – All Topics
No pictures – Pure Chemistry – 120 Questions
Directions: Choose the best answer for each question (A – E). Answers are provided below each question.
Questions 1 – 10: Lab Safety & Tools
1. A student spills a large amount of concentrated acid on their lab bench. The FIRST action should be:
A) Wipe it up with paper towels
B) Neutralize it with a strong base
C) Notify the teacher and use the spill kit
D) Add water to dilute it
E) Ignore it if it's not on skin
Answer: C
2. Which piece of equipment is MOST appropriate for accurately measuring 25.00 mL of a liquid?
A) Beaker
B) Erlenmeyer flask
C) Graduated cylinder
D) Volumetric pipette
E) Burette
Answer: D
3. The NFPA diamond label on a chemical container uses a color code. The blue section indicates:
A) Flammability hazard
B) Reactivity hazard
C) Health hazard
D) Special hazards
E) Corrosivity
Answer: C
4. A student needs to heat a test tube containing a flammable liquid. The SAFEST method is to:
A) Heat it directly over a Bunsen burner flame
B) Use a hot plate in a fume hood
C) Use a water bath
D) Heat it in a closed container
E) Use a microwave
Answer: C
5. Which of the following is the CORRECT procedure for diluting concentrated sulfuric acid?
A) Add water to the acid slowly with stirring
B) Add acid to water slowly with stirring
C) Mix them in any order quickly
D) Add both simultaneously
E) Never dilute sulfuric acid
Answer: B
6. What is the purpose of a fume hood in a chemistry lab?
A) To store chemicals safely
B) To provide a sterile environment
C) To ventilate toxic or volatile fumes
D) To heat reactions under pressure
E) To weigh precise masses
Answer: C
7. The correct method to test the odor of a chemical in the lab is:
A) Inhale deeply near the container
B) Waft the vapor toward your nose with your hand
C) Place your nose directly over the opening
D) Shake the container and smell immediately
E) Smell the stopper only
Answer: B
8. Which type of fire extinguisher should be used for a chemical fire involving flammable liquids?
A) Class A (water)
B) Class B (CO₂ or dry chemical)
C) Class C (electrical)
D) Class D (metal)
E) Class K (kitchen)
Answer: B
9. An MSDS sheet provides information about all of the following EXCEPT:
A) Physical and chemical properties
B) Health hazards
C) Cost of the chemical
D) First aid measures
E) Storage and disposal
Answer: C
10. What is the proper disposal method for solid chemical waste in a high school lab?
A) Pour it down the sink with water
B) Place it in a designated waste container
C) Throw it in the regular trash
D) Dispose of it in the fume hood
E) Leave it on the lab bench
Answer: B
Questions 11 – 20: The Science of Chemistry
11. A sample of matter has a definite shape and definite volume. This sample is most likely a:
A) Gas
B) Liquid
C) Solid
D) Plasma
E) Colloid
Answer: C
12. Which of the following is an example of a physical change?
A) Baking a cake
B) Rusting of iron
C) Sublimation of dry ice
D) Digestion of food
E) Combustion of wood
Answer: C
13. How many significant figures are in the number 0.03040?
A) 2
B) 3
C) 4
D) 5
E) 6
Answer: C
14. A student calculates the density of a metal to be 8.92 g/cm³. The actual density is 8.96 g/cm³. What is the percent error?
A) 0.45%
B) 0.89%
C) 4.5%
D) 8.9%
E) 0.04%
Answer: A
15. Which of the following is a chemical property of matter?
A) Density
B) Melting point
C) Reactivity with acid
D) Boiling point
E) Color
Answer: C
16. A mixture contains salt, sand, and iron filings. Which separation technique would remove the iron filings FIRST?
A) Filtration
B) Distillation
C) Magnetism
D) Evaporation
E) Chromatography
Answer: C
17. What is the density of a substance with a mass of 25.0 g and a volume of 10.0 cm³?
A) 0.400 g/cm³
B) 2.50 g/cm³
C) 25.0 g/cm³
D) 250 g/cm³
E) 0.250 g/cm³
Answer: B
18. Which of the following is an example of an intensive property?
A) Mass
B) Volume
C) Temperature
D) Density
E) Weight
Answer: D
19. 0.000450 expressed in scientific notation is:
A) 4.50 × 10⁻⁴
B) 4.50 × 10⁴
C) 4.50 × 10⁻³
D) 45.0 × 10⁻⁵
E) 4.5 × 10³
Answer: A
20. Which of the following is a homogeneous mixture?
A) Salad dressing
B) Granite
C) Saltwater
D) Soil
E) Sand and water
Answer: C
Questions 21 – 30: Atoms and Moles
21. An atom has 29 protons, 35 neutrons, and 29 electrons. What is its mass number?
A) 29
B) 35
C) 58
D) 64
E) 93
Answer: D
22. How many moles of atoms are in 6.02 × 10²³ atoms of silver?
A) 0.100 mol
B) 0.500 mol
C) 1.00 mol
D) 2.00 mol
E) 6.02 mol
Answer: C
23. The isotope ⁶³Cu has how many neutrons?
A) 29
B) 34
C) 35
D) 63
E) 92
Answer: B
24. What is the molar mass of aluminum nitrate, Al(NO₃)₃? (Al=27, N=14, O=16)
A) 102 g/mol
B) 165 g/mol
C) 213 g/mol
D) 231 g/mol
E) 294 g/mol
Answer: C
25. What mass of iron (Fe) contains 3.01 × 10²³ atoms? (Fe=56 g/mol)
A) 14.0 g
B) 28.0 g
C) 56.0 g
D) 84.0 g
E) 112 g
Answer: B
26. Which of the following is an isotope of carbon-12?
A) ¹²C⁺
B) ¹³C
C) ¹²N
D) ¹⁴C²⁻
E) ¹²B
Answer: B
27. A compound contains 2.0 mol of sodium, 2.0 mol of sulfur, and 6.0 mol of oxygen. What is the empirical formula?
A) NaSO₂
B) Na₂S₂O₆
C) Na₂SO₃
D) Na₂SO₄
E) NaS₂O₃
Answer: D
28. How many molecules are in 2.0 mol of H₂O?
A) 6.02 × 10²³
B) 1.20 × 10²⁴
C) 1.81 × 10²⁴
D) 2.41 × 10²⁴
E) 3.01 × 10²⁴
Answer: B
29. The average atomic mass of an element is 35.5. The element is most likely:
A) Sodium
B) Magnesium
C) Chlorine
D) Potassium
E) Calcium
Answer: C
30. Which of the following has the LARGEST number of atoms?
A) 1.0 g of He
B) 1.0 g of H₂
C) 1.0 g of C
D) 1.0 g of O₂
E) 1.0 g of N₂
Answer: B
Questions 31 – 40: The Periodic Table
31. Which element is in Period 4, Group 2?
A) Sodium
B) Magnesium
C) Calcium
D) Strontium
E) Barium
Answer: C
32. Which group has elements with a 3- charge when forming ions?
A) Group 1
B) Group 2
C) Group 15
D) Group 16
E) Group 17
Answer: C
33. Which of the following correctly ranks the elements by decreasing atomic radius?
A) K > Na > Li
B) Li > Na > K
C) Na > K > Li
D) Li > K > Na
E) K > Li > Na
Answer: A
34. Which of the following has the highest electronegativity?
A) Chlorine
B) Sulfur
C) Phosphorus
D) Silicon
E) Aluminum
Answer: A
35. The element with electron configuration [Ar]4s²3d⁶ is:
A) Iron
B) Cobalt
C) Nickel
D) Copper
E) Zinc
Answer: A
36. Which of the following is a noble gas?
A) Bromine
B) Krypton
C) Chlorine
D) Fluorine
E) Oxygen
Answer: B
37. Ionization energy generally decreases:
A) Across a period from left to right
B) Down a group
C) Across a period from right to left
D) Both A and C
E) Both B and C
Answer: E
38. Which element is a metalloid?
A) Sodium
B) Silicon
C) Chlorine
D) Iron
E) Calcium
Answer: B
39. The outermost energy level of a phosphorus atom contains how many electrons?
A) 2
B) 3
C) 5
D) 7
E) 8
Answer: C
40. The modern periodic table is arranged in order of increasing:
A) Atomic mass
B) Atomic number
C) Number of neutrons
D) Mass number
E) Reactivity
Answer: B
Questions 41 – 50: Ions and Ionic Compounds
41. The correct formula for barium phosphate is:
A) BaPO₄
B) Ba₂PO₄
C) Ba₃(PO₄)₂
D) Ba(PO₄)₂
E) Ba₂(PO₄)₃
Answer: C
42. How many electrons does a sulfide ion (S²⁻) have?
A) 14
B) 16
C) 18
D) 20
E) 22
Answer: C
43. Which of the following is NOT a characteristic of ionic compounds?
A) High melting points
B) Conduct electricity when dissolved in water
C) Formed between metals and nonmetals
D) Usually gases at room temperature
E) Crystalline solids
Answer: D
44. The correct name for Cr₂O₃ is:
A) Chromium oxide
B) Chromium(II) oxide
C) Chromium(III) oxide
D) Chromium(VI) oxide
E) Dichromium trioxide
Answer: C
45. What is the formula for ammonium sulfate?
A) NH₄SO₄
B) (NH₄)₂SO₄
C) NH₄(SO₄)₂
D) (NH₄)₂SO₃
E) NH₄S₂O₃
Answer: B
46. Which of the following pairs of ions would form an ionic compound with the formula MX?
A) Na⁺ and S²⁻
B) Mg²⁺ and Cl⁻
C) K⁺ and F⁻
D) Al³⁺ and O²⁻
E) Ca²⁺ and N³⁻
Answer: C
47. The formula for iron(III) carbonate is:
A) FeCO₃
B) Fe₂CO₃
C) Fe₂(CO₃)₃
D) Fe₃(CO₃)₂
E) Fe(CO₃)₂
Answer: C
48. The electron configuration of an oxide ion (O²⁻) is:
A) 1s²2s²2p⁴
B) 1s²2s²2p⁵
C) 1s²2s²2p⁶
D) 1s²2s²2p⁶3s²
E) 1s²2s²2p⁶3s²3p⁴
Answer: C
49. Which of the following is a polyatomic cation?
A) Na⁺
B) Ca²⁺
C) NH₄⁺
D) Fe³⁺
E) Al³⁺
Answer: C
50. A crystal of sodium chloride is held together by:
A) Covalent bonds
B) Ionic bonds
C) Metallic bonds
D) Hydrogen bonds
E) Van der Waals forces
Answer: B
Questions 51 – 60: Covalent Compounds
Questions 51 – 60: Covalent Compounds
51. Which of the following molecules contains a coordinate covalent bond?
A) H₂O
B) NH₃
C) NH₄⁺
D) CO₂
E) CH₄
Answer: C
52. How many sigma (ฯ) and pi (ฯ) bonds are in a molecule of C₂H₂?
A) 1 ฯ, 0 ฯ
B) 2 ฯ, 1 ฯ
C) 3 ฯ, 2 ฯ
D) 3 ฯ, 3 ฯ
E) 2 ฯ, 2 ฯ
Answer: C
53. Which of the following molecules is polar?
A) CCl₄
B) CO₂
C) SO₂
D) BF₃
E) BeCl₂
Answer: C
54. The VSEPR geometry of SF₆ is:
A) Tetrahedral
B) Octahedral
C) Trigonal bipyramidal
D) Square planar
E) Linear
Answer: B
55. Which of the following molecules does NOT obey the octet rule?
A) CH₄
B) NH₃
C) H₂O
D) PCl₅
E) CO₂
Answer: D
56. The correct name for CCl₄ is:
A) Carbon chloride
B) Carbon tetrachloride
C) Carbon tetracloride
D) Monocarbon tetrachloride
E) Tetrachlorocarbon
Answer: B
57. Which intermolecular force is responsible for the high boiling point of water?
A) London dispersion forces
B) Dipole-dipole forces
C) Hydrogen bonding
D) Ionic bonding
E) Covalent bonding
Answer: C
58. The bond angle in a trigonal pyramidal molecule like NH₃ is approximately:
A) 90°
B) 104.5°
C) 107°
D) 109.5°
E) 120°
Answer: C
59. Which of the following correctly orders bond length from longest to shortest?
A) Single > Double > Triple
B) Triple > Double > Single
C) Double > Single > Triple
D) Single > Triple > Double
E) Triple > Single > Double
Answer: A
60. The Lewis structure of CO shows:
A) A single bond
B) A double bond
C) A triple bond
D) Two single bonds
E) One single and one lone pair
Answer: C
Questions 61 – 70: The Mole and Chemical Composition
61. How many grams of Na₂CO₃ are in 0.500 mol? (Na=23, C=12, O=16)
A) 53.0 g
B) 62.5 g
C) 106 g
D) 159 g
E) 212 g
Answer: A
62. A compound has the formula C₆H₁₂O₆. What is the percent composition of hydrogen?
A) 4.44%
B) 6.67%
C) 40.0%
D) 53.3%
E) 66.7%
Answer: B
63. A compound contains 92.3% carbon and 7.7% hydrogen. What is its empirical formula?
A) CH
B) CH₂
C) CH₃
D) C₂H₃
E) C₂H₅
Answer: A
64. The empirical formula of a compound is NO₂. If its molar mass is 92 g/mol, what is its molecular formula?
A) NO₂
B) N₂O₄
C) N₃O₆
D) N₄O₈
E) N₂O₂
Answer: B
65. How many moles of oxygen atoms are in 1.0 mol of Ca₃(PO₄)₂?
A) 2.0 mol
B) 4.0 mol
C) 6.0 mol
D) 8.0 mol
E) 12.0 mol
Answer: D
66. What is the mass of 2.50 mol of C₂H₅OH? (C=12, H=1, O=16)
A) 23.0 g
B) 46.0 g
C) 69.0 g
D) 92.0 g
E) 115 g
Answer: E
67. A sample contains 6.02 × 10²³ molecules of CO₂. What is its mass? (C=12, O=16)
A) 12.0 g
B) 28.0 g
C) 44.0 g
D) 66.0 g
E) 88.0 g
Answer: C
68. How many grams of nitrogen are in 2.0 mol of NH₃? (N=14, H=1)
A) 14.0 g
B) 28.0 g
C) 34.0 g
D) 42.0 g
E) 56.0 g
Answer: B
69. Which of the following has the greatest mass?
A) 1.0 mol of H₂O
B) 1.0 mol of CO₂
C) 1.0 mol of NaCl
D) 1.0 mol of CH₄
E) 1.0 mol of NH₃
Answer: C
70. A compound has an empirical formula of CH₂O and a molar mass of 180 g/mol. Its molecular formula is:
A) CH₂O
B) C₂H₄O₂
C) C₃H₆O₃
D) C₆H₁₂O₆
E) C₄H₈O₄
Answer: D
Questions 71 – 80: Chemical Equations and Stoichiometry
71. When the equation Fe₂O₃ + CO → Fe + CO₂ is balanced, the coefficient of CO is:
A) 1
B) 2
C) 3
D) 4
E) 6
Answer: C
72. How many moles of NH₃ are produced from 3.0 mol of N₂? N₂ + 3H₂ → 2NH₃
A) 1.5 mol
B) 3.0 mol
C) 4.5 mol
D) 6.0 mol
E) 9.0 mol
Answer: D
73. What mass of CaO is produced from 50.0 g of CaCO₃? CaCO₃ → CaO + CO₂ (Ca=40, C=12, O=16)
A) 14.0 g
B) 22.4 g
C) 28.0 g
D) 44.0 g
E) 56.0 g
Answer: C
74. If 2.0 mol of Al reacts with 3.0 mol of Cl₂, what is the limiting reactant? 2Al + 3Cl₂ → 2AlCl₃
A) Al
B) Cl₂
C) AlCl₃
D) Both are limiting
E) Neither is limiting
Answer: B
75. What is the percent yield if 8.0 g of product is obtained from a reaction with a theoretical yield of 10.0 g?
A) 60%
B) 70%
C) 80%
D) 90%
E) 100%
Answer: C
76. How many liters of CO₂ (at STP) are produced when 2.0 mol of C₃H₈ burns? C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
A) 44.8 L
B) 67.2 L
C) 89.6 L
D) 134.4 L
E) 179.2 L
Answer: D
77. For the reaction 2KClO₃ → 2KCl + 3O₂, how many grams of O₂ are produced from 24.5 g of KClO₃? (K=39, Cl=35.5, O=16)
A) 4.8 g
B) 6.4 g
C) 9.6 g
D) 12.8 g
E) 19.2 g
Answer: C
78. How many moles of H₂O are produced when 4.0 g of H₂ reacts with excess O₂? 2H₂ + O₂ → 2H₂O (H=1, O=16)
A) 1.0 mol
B) 1.5 mol
C) 2.0 mol
D) 3.0 mol
E) 4.0 mol
Answer: C
79. The reaction 2Mg + O₂ → 2MgO is a:
A) Synthesis reaction
B) Decomposition reaction
C) Single replacement reaction
D) Double replacement reaction
E) Combustion reaction
Answer: A
80. What is the coefficient of H₂O when the equation C₂H₆ + O₂ → CO₂ + H₂O is balanced?
A) 2
B) 3
C) 4
D) 6
E) 8
Answer: D
✅ Questions 51-80 Complete. Continue to Questions 81-120 in the next section.
Posted for practice purposes only.
Questions 81 – 90: Thermochemistry & Causes of Change
81. A reaction has ฮH = +45 kJ and ฮS = +150 J/K. At what temperature does the reaction become spontaneous?
A) 150 K
B) 200 K
C) 300 K
D) 450 K
E) 600 K
Answer: C
82. How much heat is required to vaporize 36.0 g of water? (ฮH_vap = 40.7 kJ/mol, H=1, O=16)
A) 40.7 kJ
B) 81.4 kJ
C) 122.1 kJ
D) 162.8 kJ
E) 203.5 kJ
Answer: B
83. According to Hess's Law, the enthalpy change of a reaction depends only on:
A) The pathway taken
B) The initial and final states
C) The number of steps
D) The catalyst used
E) The temperature change
Answer: B
84. A system releases 150 J of heat and does 75 J of work on the surroundings. What is ฮE?
A) +225 J
B) +75 J
C) -75 J
D) -150 J
E) -225 J
Answer: E
85. Which of the following processes has ฮS > 0?
A) 2NO₂(g) → N₂O₄(g)
B) H₂O(l) → H₂O(s)
C) NH₄Cl(s) → NH₄⁺(aq) + Cl⁻(aq)
D) CO₂(g) → CO₂(s)
E) N₂(g) + 3H₂(g) → 2NH₃(g)
Answer: C
86. The standard enthalpy of formation of O₂(g) is:
A) +100 kJ/mol
B) -100 kJ/mol
C) 0 kJ/mol
D) +200 kJ/mol
E) -200 kJ/mol
Answer: C
87. If ฮH = -80 kJ and ฮS = -200 J/K, the reaction is spontaneous at:
A) Low temperatures only
B) High temperatures only
C) All temperatures
D) No temperatures
E) Exactly 400 K
Answer: A
88. What is the heat required to melt 2.0 mol of ice at 0°C? (ฮH_fus = 6.01 kJ/mol)
A) 6.01 kJ
B) 12.0 kJ
C) 24.0 kJ
D) 36.0 kJ
E) 48.0 kJ
Answer: B
89. The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero is:
A) Positive
B) Negative
C) Zero
D) Infinite
E) Undefined
Answer: C
90. A 15.0 g sample of a metal absorbs 150 J of heat and its temperature increases from 25.0°C to 35.0°C. What is the specific heat of the metal?
A) 0.50 J/g°C
B) 1.00 J/g°C
C) 1.50 J/g°C
D) 2.00 J/g°C
E) 2.50 J/g°C
Answer: B
Questions 91 – 100: States of Matter, Gases & Solutions
91. A gas occupies 3.0 L at 27°C. What is its volume at 127°C at constant pressure?
A) 2.0 L
B) 3.0 L
C) 4.0 L
D) 5.0 L
E) 6.0 L
Answer: C
92. What is the partial pressure of O₂ in a mixture containing 2.0 mol of O₂ and 3.0 mol of N₂ at a total pressure of 2.5 atm?
A) 0.50 atm
B) 1.00 atm
C) 1.50 atm
D) 2.00 atm
E) 2.50 atm
Answer: B
93. Which of the following correctly orders the phases by increasing particle motion?
A) Solid < Liquid < Gas
B) Gas < Liquid < Solid
C) Solid < Gas < Liquid
D) Liquid < Solid < Gas
E) Gas < Solid < Liquid
Answer: A
94. What is the molarity of a solution containing 5.0 g of NaCl in 500.0 mL of solution? (Na=23, Cl=35.5)
A) 0.085 M
B) 0.171 M
C) 0.342 M
D) 0.500 M
E) 1.00 M
Answer: B
95. The molality of a solution is defined as:
A) Moles of solute per liter of solution
B) Moles of solute per liter of solvent
C) Moles of solute per kilogram of solvent
D) Grams of solute per kilogram of solution
E) Moles of solvent per kilogram of solute
Answer: C
96. What volume of 12.0 M HCl is needed to prepare 1.0 L of 0.50 M HCl?
A) 20.8 mL
B) 41.7 mL
C) 62.5 mL
D) 83.3 mL
E) 125 mL
Answer: B
97. The freezing point depression constant (Kf) is a property of the:
A) Solute
B) Solvent
C) Solution
D) Precipitate
E) Gas phase
Answer: B
98. Which of the following will have the highest boiling point?
A) 0.50 m NaCl
B) 0.50 m CaCl₂
C) 0.50 m glucose
D) 0.50 m sucrose
E) 0.50 m methanol
Answer: B
99. The vapor pressure of a solution is always:
A) Higher than the pure solvent
B) Lower than the pure solvent
C) Equal to the pure solvent
D) Independent of the solute
E) Zero
Answer: B
100. The osmotic pressure of a solution is directly proportional to:
A) Temperature and molarity
B) Temperature only
C) Molarity only
D) Volume of the solution
E) Mass of the solute
Answer: A
Questions 101 – 110: Equilibrium & Acids/Bases
101. The equilibrium constant expression for the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) is:
A) Kc = [SO₃]² / [SO₂]²[O₂]
B) Kc = [SO₂]²[O₂] / [SO₃]²
C) Kc = [SO₃] / [SO₂][O₂]
D) Kc = [SO₃]² / [SO₂][O₂]
E) Kc = [SO₂]² / [SO₃]²[O₂]
Answer: A
102. For the reaction CaCO₃(s) ⇌ CaO(s) + CO₂(g), adding more CaCO₃ will:
A) Shift equilibrium to the right
B) Shift equilibrium to the left
C) Have no effect on the equilibrium
D) Increase the amount of CO₂
E) Decrease the amount of CaO
Answer: C
103. A solution has a pH of 3.0. What is its pOH?
A) 3.0
B) 7.0
C) 10.0
D) 11.0
E) 14.0
Answer: D
104. Which of the following is a buffer solution?
A) HCl and NaCl
B) NaOH and NaCl
C) CH₃COOH and CH₃COONa
D) H₂SO₄ and Na₂SO₄
E) NH₃ and NaCl
Answer: C
105. What is the pH of a 0.010 M solution of HCl?
A) 1.0
B) 2.0
C) 3.0
D) 4.0
E) 12.0
Answer: B
106. The conjugate acid of NH₃ is:
A) NH₂⁻
B) NH₄⁺
C) N³⁻
D) NO₃⁻
E) HNO₃
Answer: B
107. What volume of 0.200 M NaOH is needed to neutralize 50.0 mL of 0.100 M H₂SO₄?
A) 25.0 mL
B) 50.0 mL
C) 75.0 mL
D) 100 mL
E) 125 mL
Answer: B
108. Which of the following salts will produce an acidic solution when dissolved in water?
A) NaCl
B) Na₂CO₃
C) NH₄Cl
D) NaNO₃
E) KCl
Answer: C
109. The Henderson-Hasselbalch equation is used to calculate:
A) The pH of a buffer solution
B) The pH of a strong acid
C) The pH of a strong base
D) The concentration of a solution
E) The molar mass of a compound
Answer: A
110. The equivalence point in a titration is the point where:
A) The indicator changes color
B) The moles of acid equal the moles of base
C) The pH is exactly 7
D) The reaction stops
E) The temperature changes
Answer: B
Questions 111 – 120: Reaction Rates, Redox, Nuclear, Organic & Biological Chemistry
111. The rate law for a reaction is rate = k[A][B]². If the concentration of A is tripled and B is halved, the rate will:
A) Increase by a factor of 3
B) Decrease by a factor of 3
C) Increase by a factor of 6
D) Decrease by a factor of 6
E) Stay the same
Answer: A
112. A catalyst increases the rate of a reaction by:
A) Increasing the temperature
B) Decreasing the activation energy
C) Increasing the concentration of reactants
D) Changing the equilibrium constant
E) Increasing the surface area
Answer: B
113. In the reaction 2K + Cl₂ → 2KCl, which element is oxidized?
A) K
B) Cl₂
C) KCl
D) Both K and Cl₂
E) Neither
Answer: A
114. What is the oxidation state of sulfur in H₂SO₄?
A) +2
B) +3
C) +4
D) +5
E) +6
Answer: E
115. In a galvanic cell, the substance that is oxidized is the:
A) Cathode
B) Anode
C) Salt bridge
D) Electrolyte
E) Neither electrode
Answer: B
116. Which of the following is the strongest reducing agent?
A) Li
B) Na
C) K
D) Mg
E) Ca
Answer: A
117. What is the oxidation state of manganese in KMnO₄?
A) +4
B) +5
C) +6
D) +7
E) +8
Answer: D
118. The oxidizing agent is the substance that:
A) Loses electrons
B) Gains electrons
C) Is oxidized
D) Acts as a catalyst
E) Is inert
Answer: B
119. In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, which substance is reduced?
A) Zn
B) Cu²⁺
C) Zn²⁺
D) Cu
E) Both Zn and Cu
Answer: B
120. What is the standard cell potential (E°cell) for the reaction Zn + Cu²⁺ → Zn²⁺ + Cu? (E°Zn²⁺/Zn = -0.76 V, E°Cu²⁺/Cu = +0.34 V)
A) -1.10 V
B) 1.10 V
C) 0.42 V
D) -0.42 V
E) 1.50 V
Answer: B
✅ END OF ULTIMATE MOCK EXAM – All 120 Questions Complete!
Summary of the 120-Question Exam:
| Topic Area | Questions |
|---|---|
| Lab Safety & Tools | 1-10 |
| Science of Chemistry | 11-20 |
| Atoms and Moles | 21-30 |
| Periodic Table | 31-40 |
| Ions and Ionic Compounds | 41-50 |
| Covalent Compounds | 51-60 |
| The Mole & Chemical Composition | 61-70 |
| Chemical Equations (15 questions) | 71-80, 101-102 |
| Thermochemistry | 81-90 |
| States of Matter, Gases, Solutions | 91-100 |
| Equilibrium & Acids/Bases | 101-110 |
| Reaction Rates, Redox (7), Nuclear, Organic, Biological | 111-120 |
Posted for practice purposes only.
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