Q. Which of the following reactions has a negative enthalpy change?
A.
Dissolving NaCl in water
B.
Photosynthesis
C.
Respiration
D.
Melting of ice
Show solution
Solution
Respiration is an exothermic reaction that releases energy, resulting in a negative enthalpy change.
Correct Answer:
C
— Respiration
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Q. Which of the following reactions has a positive ΔG at standard conditions?
A.
Combustion of glucose
B.
Formation of water from hydrogen and oxygen
C.
Dissolution of salt in water
D.
Decomposition of hydrogen peroxide
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Solution
The decomposition of hydrogen peroxide is non-spontaneous under standard conditions, resulting in a positive ΔG.
Correct Answer:
D
— Decomposition of hydrogen peroxide
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Q. Which of the following reactions has a positive ΔH and a positive ΔS?
A.
Combustion of fuels
B.
Dissolution of salts
C.
Sublimation of dry ice
D.
Formation of water from hydrogen and oxygen
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Solution
Sublimation of dry ice (solid CO2 to gas) has a positive ΔH (endothermic) and a positive ΔS (increase in disorder).
Correct Answer:
C
— Sublimation of dry ice
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Q. Which of the following reactions has the highest enthalpy change?
A.
Dissolving NaCl in water
B.
Combustion of propane
C.
Formation of NH3 from N2 and H2
D.
Sublimation of dry ice
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Solution
The combustion of propane releases a large amount of energy, resulting in the highest enthalpy change among the options.
Correct Answer:
B
— Combustion of propane
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Q. Which of the following reactions is a redox reaction?
A.
H2 + Cl2 → 2HCl
B.
NaOH + HCl → NaCl + H2O
C.
CaCO3 → CaO + CO2
D.
C6H12O6 + 6O2 → 6CO2 + 6H2O
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Solution
The combustion of glucose is a redox reaction where glucose is oxidized.
Correct Answer:
D
— C6H12O6 + 6O2 → 6CO2 + 6H2O
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Q. Which of the following reactions is expected to have a positive change in entropy?
A.
N2(g) + 3H2(g) → 2NH3(g)
B.
C(s) + O2(g) → CO2(g)
C.
2H2O(l) → 2H2(g) + O2(g)
D.
CaCO3(s) → CaO(s) + CO2(g)
Show solution
Solution
The decomposition of liquid water into gaseous hydrogen and oxygen increases the number of gas molecules, leading to a positive change in entropy.
Correct Answer:
C
— 2H2O(l) → 2H2(g) + O2(g)
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Q. Which of the following reactions is likely to have a negative ΔG?
A.
Combustion of hydrocarbons.
B.
Formation of ice from water at 0°C.
C.
Dissolution of salt in water.
D.
Decomposition of hydrogen peroxide.
Show solution
Solution
The combustion of hydrocarbons is highly exothermic and typically has a negative ΔG, indicating spontaneity.
Correct Answer:
A
— Combustion of hydrocarbons.
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Q. Which of the following reactions is spontaneous at all temperatures?
A.
ΔH < 0 and ΔS < 0
B.
ΔH > 0 and ΔS > 0
C.
ΔH < 0 and ΔS > 0
D.
ΔH > 0 and ΔS < 0
Show solution
Solution
A reaction with ΔH < 0 and ΔS > 0 is spontaneous at all temperatures because it results in a negative ΔG.
Correct Answer:
C
— ΔH < 0 and ΔS > 0
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Q. Which of the following reactions will have a negative ΔG at high temperatures?
A.
Exothermic reactions with negative ΔS
B.
Endothermic reactions with positive ΔS
C.
Exothermic reactions with positive ΔS
D.
Endothermic reactions with negative ΔS
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Solution
Endothermic reactions with positive ΔS can have a negative ΔG at high temperatures due to the TΔS term becoming significant.
Correct Answer:
B
— Endothermic reactions with positive ΔS
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Q. Which of the following represents a physical change?
A.
Burning wood
B.
Dissolving sugar in water
C.
Rusting of iron
D.
Cooking an egg
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Solution
Dissolving sugar in water is a physical change as it does not alter the chemical composition of sugar.
Correct Answer:
B
— Dissolving sugar in water
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Q. Which of the following represents an endothermic reaction?
A.
Combustion of gasoline
B.
Dissolving ammonium nitrate in water
C.
Respiration
D.
Rusting of iron
Show solution
Solution
Dissolving ammonium nitrate in water absorbs heat, making it an endothermic reaction.
Correct Answer:
B
— Dissolving ammonium nitrate in water
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Q. Which of the following represents the correct relationship between moles and mass?
A.
Moles = Mass / Molar Mass
B.
Mass = Moles x Molar Mass
C.
Molar Mass = Mass / Moles
D.
All of the above
Show solution
Solution
All the given relationships are correct and represent the conversion between moles, mass, and molar mass.
Correct Answer:
D
— All of the above
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Q. Which of the following represents the correct relationship between moles, mass, and molar mass?
A.
moles = mass × molar mass
B.
mass = moles × molar mass
C.
molar mass = mass / moles
D.
mass = moles / molar mass
Show solution
Solution
The correct relationship is mass = moles × molar mass.
Correct Answer:
B
— mass = moles × molar mass
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Q. Which of the following represents the enthalpy change for a reaction at constant pressure?
Show solution
Solution
The enthalpy change for a reaction at constant pressure is represented by ΔH.
Correct Answer:
B
— ΔH
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Q. Which of the following represents the number of particles in one mole of a substance?
A.
6.022 x 10^23
B.
3.14 x 10^22
C.
1.6 x 10^19
D.
9.11 x 10^28
Show solution
Solution
Avogadro's number is 6.022 x 10^23, which represents the number of particles in one mole.
Correct Answer:
A
— 6.022 x 10^23
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Q. Which of the following salts will produce a basic solution when dissolved in water?
A.
NaCl
B.
KNO3
C.
NH4Cl
D.
Na2CO3
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Solution
Na2CO3 is a salt of a weak acid (H2CO3) and a strong base (NaOH), thus it will produce a basic solution.
Correct Answer:
D
— Na2CO3
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Q. Which of the following sets of quantum numbers corresponds to a 3p electron?
A.
n=3, l=0, m_l=0
B.
n=3, l=1, m_l=1
C.
n=2, l=1, m_l=0
D.
n=3, l=2, m_l=0
Show solution
Solution
For a 3p electron, n=3 and l=1. The magnetic quantum number m_l can be -1, 0, or +1.
Correct Answer:
B
— n=3, l=1, m_l=1
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Q. Which of the following sets of quantum numbers corresponds to an electron in a 4d orbital?
A.
n=4, l=0, m_l=0
B.
n=4, l=2, m_l=1
C.
n=3, l=2, m_l=2
D.
n=4, l=1, m_l=0
Show solution
Solution
For a 4d orbital, n=4 and l=2. The m_l value can be -2, -1, 0, +1, +2.
Correct Answer:
B
— n=4, l=2, m_l=1
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Q. Which of the following sets of quantum numbers is not allowed?
A.
n=2, l=1, m_l=0
B.
n=3, l=2, m_l=2
C.
n=1, l=0, m_l=1
D.
n=4, l=3, m_l=-3
Show solution
Solution
For l=0, m_l can only be 0. Therefore, n=1, l=0, m_l=1 is not allowed.
Correct Answer:
C
— n=1, l=0, m_l=1
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Q. Which of the following sets of quantum numbers is not possible?
A.
n=3, l=2, m_l=1
B.
n=2, l=1, m_l=2
C.
n=4, l=3, m_l=0
D.
n=1, l=0, m_l=0
Show solution
Solution
For l=1, m_l can only be -1, 0, or +1. Therefore, m_l=2 is not possible.
Correct Answer:
B
— n=2, l=1, m_l=2
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Q. Which of the following solutions has the highest boiling point?
A.
0.1 M NaCl
B.
0.1 M KCl
C.
0.1 M CaCl2
D.
0.1 M glucose
Show solution
Solution
CaCl2 dissociates into 3 ions (Ca^2+ and 2 Cl^-), leading to the highest boiling point elevation among the options.
Correct Answer:
C
— 0.1 M CaCl2
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Q. Which of the following solutions has the highest concentration?
A.
0.1 M NaCl
B.
0.2 M KCl
C.
0.05 M CaCl2
D.
0.3 M MgSO4
Show solution
Solution
Concentration in terms of molarity: 0.1 M NaCl = 0.1, 0.2 M KCl = 0.2, 0.05 M CaCl2 = 0.15 (0.05*3), 0.3 M MgSO4 = 0.3. Highest is 0.3 M MgSO4.
Correct Answer:
D
— 0.3 M MgSO4
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Q. Which of the following solutions will have the highest boiling point?
A.
0.1 M NaCl
B.
0.1 M KCl
C.
0.1 M glucose
D.
0.1 M MgCl2
Show solution
Solution
0.1 M MgCl2 will have the highest boiling point due to the highest van 't Hoff factor (i = 3).
Correct Answer:
D
— 0.1 M MgCl2
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Q. Which of the following solutions will have the lowest freezing point?
A.
0.1 M NaCl
B.
0.1 M KBr
C.
0.1 M MgCl2
D.
0.1 M glucose
Show solution
Solution
MgCl2 dissociates into 3 ions, leading to the greatest freezing point depression among the options.
Correct Answer:
C
— 0.1 M MgCl2
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Q. Which of the following solutions will have the lowest vapor pressure?
A.
0.1 M NaCl
B.
0.1 M KBr
C.
0.1 M MgCl2
D.
0.1 M glucose
Show solution
Solution
MgCl2 dissociates into 3 ions, leading to the highest number of solute particles and thus the lowest vapor pressure.
Correct Answer:
C
— 0.1 M MgCl2
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Q. Which of the following species exhibits sp3d hybridization?
A.
SF4
B.
XeF2
C.
NH3
D.
C2H4
Show solution
Solution
In SF4, the sulfur atom is sp3d hybridized, resulting in a seesaw molecular geometry.
Correct Answer:
A
— SF4
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Q. Which of the following species has a bond order of 1?
Show solution
Solution
F2 has a bond order of 1, calculated as (8 bonding electrons - 6 antibonding electrons)/2 = 1.
Correct Answer:
C
— F2
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Q. Which of the following species has a central atom with sp3 hybridization?
A.
CCl4
B.
CO2
C.
BF3
D.
H2O
Show solution
Solution
In CCl4, the central carbon atom is sp3 hybridized, forming a tetrahedral geometry.
Correct Answer:
A
— CCl4
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Q. Which of the following species has a linear geometry due to hybridization?
A.
H2O
B.
CO2
C.
NH3
D.
CH4
Show solution
Solution
CO2 has a linear geometry due to the sp hybridization of the carbon atom.
Correct Answer:
B
— CO2
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Q. Which of the following species has a linear molecular geometry?
A.
BeCl2
B.
NH3
C.
H2O
D.
CH3Cl
Show solution
Solution
BeCl2 has two bonding pairs and no lone pairs, resulting in a linear molecular geometry.
Correct Answer:
A
— BeCl2
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Showing 1351 to 1380 of 1494 (50 Pages)
Physical Chemistry MCQ & Objective Questions
Physical Chemistry is a crucial branch of chemistry that combines principles of physics and chemistry to explain how matter behaves. Mastering this subject is essential for students preparing for school exams and competitive tests. Practicing MCQs and objective questions in Physical Chemistry not only enhances conceptual clarity but also boosts your chances of scoring better in exams. Engaging with practice questions helps identify important topics and reinforces learning.
What You Will Practise Here
Thermodynamics: Laws, concepts, and applications
Kinetics: Rate laws, reaction mechanisms, and factors affecting reaction rates
Equilibrium: Chemical equilibrium, Le Chatelier's principle, and equilibrium constants
Quantum Chemistry: Basic principles and applications in atomic structure
Electrochemistry: Redox reactions, electrochemical cells, and Nernst equation
Solutions: Colligative properties and their calculations
Acids and Bases: pH calculations, buffer solutions, and titration curves
Exam Relevance
Physical Chemistry is a significant part of the syllabus for CBSE, State Boards, NEET, and JEE. Questions often focus on theoretical concepts, numerical problems, and application-based scenarios. Common patterns include direct questions on laws of thermodynamics, calculations involving reaction rates, and conceptual questions on equilibrium. Familiarity with these patterns can greatly enhance your exam preparation.
Common Mistakes Students Make
Misunderstanding the application of thermodynamic laws in different scenarios
Confusing reaction rates with equilibrium constants
Overlooking the significance of units in calculations
Neglecting to practice numerical problems, leading to poor time management during exams
FAQs
Question: What are the key topics to focus on in Physical Chemistry for exams?Answer: Focus on thermodynamics, kinetics, equilibrium, and electrochemistry as these are frequently tested.
Question: How can I improve my performance in Physical Chemistry MCQs?Answer: Regular practice of MCQs and understanding the underlying concepts will significantly improve your performance.
Now is the time to enhance your understanding of Physical Chemistry! Dive into our practice MCQs and test your knowledge to excel in your exams. Your success starts with practice!