[OHIO STATE CHEM1210 GENERAL CHEMISTRY] – EXAM-STYLE QUESTIONS AND
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | 2026/27 LATEST UPDATE | EXAM PREP | STUDY GUIDE |
PRACTICE TEST
SECTION ONE: QUESTIONS 1-50
1. A sample of an unknown liquid has a mass of 25.6 g and occupies a volume
of 32.0 mL. What is the density of this liquid, and would it float on water
(density = 1.00 g/mL)?
A. 0.800 g/mL, float
B. 0.800 g/mL, sink
C. 1.25 g/mL, float
D. 1.25 g/mL, sink
Correct Answer: A. 0.800 g/mL, float
Rationale: Density is mass divided by volume (25.6 g / 32.0 mL = 0.800 g/mL). A
substance with a density lower than that of water (1.00 g/mL) will float. Options C
and D represent an inverted ratio, and option B correctly identifies the density but
incorrectly predicts the buoyancy.**
2. Which of the following is an example of a chemical property?
A. Boiling point of ethanol is 78.4 °C
B. Density of lead is 11.34 g/cm³
C. Iron reacts with oxygen to form rust
D. Melting point of sodium chloride is 801 °C
Correct Answer: C. Iron reacts with oxygen to form rust
Rationale: A chemical property describes a substance's ability to undergo a
,chemical change. Reactivity with oxygen is a chemical change. Options A, B, and D
are all physical properties that can be observed without changing the substance's
chemical identity.**
3. A student needs to prepare 250.0 mL of a 0.150 M solution of NaCl. How
many grams of NaCl (molar mass = 58.44 g/mol) are required?
A. 0.375 g
B. 2.19 g
C. 21.9 g
D. 3.75 g
Correct Answer: B. 2.19 g
Rationale: First, calculate the moles of NaCl needed: moles = Molarity × Volume
(L) = 0.150 mol/L × 0.250 L = 0.0375 mol. Then, convert moles to grams: 0.0375
mol × 58.44 g/mol = 2.19 g. Option A miscalculates the volume, option C has a
misplaced decimal, and option D is off by a factor of 10.**
4. An isotope of an element contains 26 protons, 30 neutrons, and 26 electrons.
What is the correct isotopic notation for this atom?
A. ⁵⁶Fe
B. ⁵⁶Zn
C. ³⁰Zn
D. ⁵²Cr
Correct Answer: A. ⁵⁶Fe
Rationale: The number of protons (26) defines the element as Iron (Fe). The mass
number is the sum of protons and neutrons (26 + 30 = 56). Thus, the isotope is
iron-56, written as ⁵⁶Fe. Options B and C have the wrong element, and option D
uses the incorrect mass number and element.**
,5. What is the wavelength of a photon of light with a frequency of 6.0 × 10¹⁴
s⁻¹? (c = 3.00 × 10⁸ m/s)
A. 1.8 × 10²³ m
B. 5.0 × 10⁻⁷ m
C. 5.0 × 10⁵ m
D. 2.0 × 10⁶ m
Correct Answer: B. 5.0 × 10⁻⁷ m
Rationale: The relationship between wavelength (λ) and frequency (ν) is c = λν.
Solving for λ gives λ = c/ν = (3.00 × 10⁸ m/s) / (6.0 × 10¹⁴ s⁻¹) = 5.0 × 10⁻⁷ m.
Options A, C, and D are results of incorrect algebraic manipulation or unit errors.**
6. Which of the following elements has the largest atomic radius?
A. Fluorine
B. Carbon
C. Sodium
D. Aluminum
Correct Answer: C. Sodium
Rationale: Atomic radius generally increases as you move down a group and
decreases as you move left to right across a period. Of the choices, Sodium is
farthest to the left and in the third period, giving it the largest radius. Fluorine and
Carbon are in period 2, and Aluminum, while in period 3, is to the right of
Sodium.**
7. A chemical reaction releases 25 kJ of energy. This process is described as:
A. Endothermic with a positive ΔH
B. Endothermic with a negative ΔH
, C. Exothermic with a positive ΔH
D. Exothermic with a negative ΔH
Correct Answer: D. Exothermic with a negative ΔH
Rationale: An exothermic process releases energy to its surroundings, resulting in a
negative change in enthalpy (ΔH). Endothermic reactions absorb energy and have a
positive ΔH. Options A and B incorrectly classify the reaction as endothermic, and
option C misidentifies the sign of ΔH.**
8. What is the correct electron configuration for a neutral calcium atom (Z =
20)?
A. 1s²2s²2p⁶3s²3p⁶4s²
B. 1s²2s²2p⁶3s²3p⁶4s¹3d¹
C. 1s²2s²2p⁶3s²3p⁶4p²
D. 1s²2s²2p⁶3s²3p⁶3d²
Correct Answer: A. 1s²2s²2p⁶3s²3p⁶4s²
Rationale: Calcium has 20 electrons. The Aufbau principle dictates that the 4s
orbital is filled before the 3d orbital. Therefore, the correct configuration is
1s²2s²2p⁶3s²3p⁶4s². Options B, C, and D violate this principle or have incorrect
orbital assignments.**
9. In the reaction 2H₂(g) + O₂(g) → 2H₂O(l), what is the oxidation state of
oxygen in the products?
A. 0
B. -1
C. -2
D. +2
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | 2026/27 LATEST UPDATE | EXAM PREP | STUDY GUIDE |
PRACTICE TEST
SECTION ONE: QUESTIONS 1-50
1. A sample of an unknown liquid has a mass of 25.6 g and occupies a volume
of 32.0 mL. What is the density of this liquid, and would it float on water
(density = 1.00 g/mL)?
A. 0.800 g/mL, float
B. 0.800 g/mL, sink
C. 1.25 g/mL, float
D. 1.25 g/mL, sink
Correct Answer: A. 0.800 g/mL, float
Rationale: Density is mass divided by volume (25.6 g / 32.0 mL = 0.800 g/mL). A
substance with a density lower than that of water (1.00 g/mL) will float. Options C
and D represent an inverted ratio, and option B correctly identifies the density but
incorrectly predicts the buoyancy.**
2. Which of the following is an example of a chemical property?
A. Boiling point of ethanol is 78.4 °C
B. Density of lead is 11.34 g/cm³
C. Iron reacts with oxygen to form rust
D. Melting point of sodium chloride is 801 °C
Correct Answer: C. Iron reacts with oxygen to form rust
Rationale: A chemical property describes a substance's ability to undergo a
,chemical change. Reactivity with oxygen is a chemical change. Options A, B, and D
are all physical properties that can be observed without changing the substance's
chemical identity.**
3. A student needs to prepare 250.0 mL of a 0.150 M solution of NaCl. How
many grams of NaCl (molar mass = 58.44 g/mol) are required?
A. 0.375 g
B. 2.19 g
C. 21.9 g
D. 3.75 g
Correct Answer: B. 2.19 g
Rationale: First, calculate the moles of NaCl needed: moles = Molarity × Volume
(L) = 0.150 mol/L × 0.250 L = 0.0375 mol. Then, convert moles to grams: 0.0375
mol × 58.44 g/mol = 2.19 g. Option A miscalculates the volume, option C has a
misplaced decimal, and option D is off by a factor of 10.**
4. An isotope of an element contains 26 protons, 30 neutrons, and 26 electrons.
What is the correct isotopic notation for this atom?
A. ⁵⁶Fe
B. ⁵⁶Zn
C. ³⁰Zn
D. ⁵²Cr
Correct Answer: A. ⁵⁶Fe
Rationale: The number of protons (26) defines the element as Iron (Fe). The mass
number is the sum of protons and neutrons (26 + 30 = 56). Thus, the isotope is
iron-56, written as ⁵⁶Fe. Options B and C have the wrong element, and option D
uses the incorrect mass number and element.**
,5. What is the wavelength of a photon of light with a frequency of 6.0 × 10¹⁴
s⁻¹? (c = 3.00 × 10⁸ m/s)
A. 1.8 × 10²³ m
B. 5.0 × 10⁻⁷ m
C. 5.0 × 10⁵ m
D. 2.0 × 10⁶ m
Correct Answer: B. 5.0 × 10⁻⁷ m
Rationale: The relationship between wavelength (λ) and frequency (ν) is c = λν.
Solving for λ gives λ = c/ν = (3.00 × 10⁸ m/s) / (6.0 × 10¹⁴ s⁻¹) = 5.0 × 10⁻⁷ m.
Options A, C, and D are results of incorrect algebraic manipulation or unit errors.**
6. Which of the following elements has the largest atomic radius?
A. Fluorine
B. Carbon
C. Sodium
D. Aluminum
Correct Answer: C. Sodium
Rationale: Atomic radius generally increases as you move down a group and
decreases as you move left to right across a period. Of the choices, Sodium is
farthest to the left and in the third period, giving it the largest radius. Fluorine and
Carbon are in period 2, and Aluminum, while in period 3, is to the right of
Sodium.**
7. A chemical reaction releases 25 kJ of energy. This process is described as:
A. Endothermic with a positive ΔH
B. Endothermic with a negative ΔH
, C. Exothermic with a positive ΔH
D. Exothermic with a negative ΔH
Correct Answer: D. Exothermic with a negative ΔH
Rationale: An exothermic process releases energy to its surroundings, resulting in a
negative change in enthalpy (ΔH). Endothermic reactions absorb energy and have a
positive ΔH. Options A and B incorrectly classify the reaction as endothermic, and
option C misidentifies the sign of ΔH.**
8. What is the correct electron configuration for a neutral calcium atom (Z =
20)?
A. 1s²2s²2p⁶3s²3p⁶4s²
B. 1s²2s²2p⁶3s²3p⁶4s¹3d¹
C. 1s²2s²2p⁶3s²3p⁶4p²
D. 1s²2s²2p⁶3s²3p⁶3d²
Correct Answer: A. 1s²2s²2p⁶3s²3p⁶4s²
Rationale: Calcium has 20 electrons. The Aufbau principle dictates that the 4s
orbital is filled before the 3d orbital. Therefore, the correct configuration is
1s²2s²2p⁶3s²3p⁶4s². Options B, C, and D violate this principle or have incorrect
orbital assignments.**
9. In the reaction 2H₂(g) + O₂(g) → 2H₂O(l), what is the oxidation state of
oxygen in the products?
A. 0
B. -1
C. -2
D. +2
