Q.1 Which of the following is an example of an intensive property?
Mass
Volume
Density
Energy
Explanation - Intensive properties do not depend on the amount of substance. Density remains the same regardless of sample size, unlike mass or volume.
Correct answer is: Density
Q.2 What is the SI unit of enthalpy?
Joule
Calorie
Watt
Newton
Explanation - Enthalpy is a measure of heat content and has the same unit as energy, which is the joule (J) in SI units.
Correct answer is: Joule
Q.3 The ideal gas equation is given as:
PV = nRT
P = nRT/V
PV = NkT
All of the above
Explanation - The ideal gas equation can be written in multiple equivalent forms: PV=nRT or PV=NkT depending on representation.
Correct answer is: All of the above
Q.4 Which law states that the volume of a gas is inversely proportional to pressure at constant temperature?
Boyle's Law
Charles's Law
Avogadro's Law
Graham's Law
Explanation - Boyle’s law states P ∝ 1/V at constant temperature, meaning when pressure increases, volume decreases proportionally.
Correct answer is: Boyle's Law
Q.5 Which of the following is NOT a state function?
Internal energy
Work
Enthalpy
Entropy
Explanation - State functions depend only on the current state, not the path. Work depends on the process path, hence is not a state function.
Correct answer is: Work
Q.6 The energy required to remove an electron from a gaseous atom is called:
Electron affinity
Ionization energy
Electronegativity
Work function
Explanation - Ionization energy is defined as the minimum energy required to remove an electron from a gaseous atom in its ground state.
Correct answer is: Ionization energy
Q.7 The unit of rate constant for a second-order reaction is:
s⁻¹
mol L⁻¹ s⁻¹
L mol⁻¹ s⁻¹
mol² L⁻² s⁻¹
Explanation - For a second-order reaction, rate constant k has dimensions of (concentration⁻¹ × time⁻¹), i.e. L mol⁻¹ s⁻¹.
Correct answer is: L mol⁻¹ s⁻¹
Q.8 According to Le Chatelier’s principle, increasing pressure favors the reaction:
That produces more gas moles
That produces fewer gas moles
That absorbs heat
That releases heat
Explanation - Higher pressure favors the side with fewer gas molecules to reduce the stress caused by pressure.
Correct answer is: That produces fewer gas moles
Q.9 The pH of a 0.001 M HCl solution is approximately:
1
2
3
11
Explanation - pH = -log[H⁺]. Here [H⁺] = 0.001 = 10⁻³, hence pH = 3.
Correct answer is: 3
Q.10 Which of the following processes is always endothermic?
Condensation
Freezing
Evaporation
Neutralization
Explanation - Evaporation requires energy to overcome intermolecular forces, making it always endothermic.
Correct answer is: Evaporation
Q.11 What is the value of Avogadro’s number?
6.022 × 10²²
6.022 × 10²³
3.14 × 10²²
9.81 × 10²³
Explanation - Avogadro’s number is 6.022 × 10²³ mol⁻¹, the number of particles in one mole of substance.
Correct answer is: 6.022 × 10²³
Q.12 Which type of bond is strongest among the following?
Hydrogen bond
Covalent bond
Ionic bond
Van der Waals forces
Explanation - Covalent bonds involve sharing of electron pairs and are generally stronger than ionic and intermolecular forces.
Correct answer is: Covalent bond
Q.13 Entropy is a measure of:
Energy
Order
Disorder
Temperature
Explanation - Entropy quantifies randomness or disorder in a system; higher entropy means higher disorder.
Correct answer is: Disorder
Q.14 At 0 K, the entropy of a perfect crystal is:
Maximum
Zero
Infinite
Constant
Explanation - According to the third law of thermodynamics, entropy of a perfect crystal at absolute zero is zero.
Correct answer is: Zero
Q.15 Which factor does NOT affect the equilibrium constant?
Temperature
Catalyst
Nature of reactants
Heat of reaction
Explanation - Catalysts speed up attainment of equilibrium but do not change the equilibrium constant.
Correct answer is: Catalyst
Q.16 The heat required to raise the temperature of 1 gram of a substance by 1°C is called:
Specific heat capacity
Molar heat capacity
Latent heat
Heat of fusion
Explanation - Specific heat capacity is defined as the amount of heat required to raise 1 g of substance by 1°C.
Correct answer is: Specific heat capacity
Q.17 Which of the following is NOT a colligative property?
Relative lowering of vapor pressure
Elevation of boiling point
Freezing point depression
Heat capacity
Explanation - Colligative properties depend on solute particle number. Heat capacity is an extensive property, not colligative.
Correct answer is: Heat capacity
Q.18 What type of reaction is 2H₂ + O₂ → 2H₂O?
Decomposition
Combination
Displacement
Redox
Explanation - This reaction involves two reactants forming one product, hence a combination reaction.
Correct answer is: Combination
Q.19 The unit of molarity is:
mol L⁻¹
mol m⁻³
g L⁻¹
kg mol⁻¹
Explanation - Molarity is defined as moles of solute per liter of solution, so unit is mol L⁻¹.
Correct answer is: mol L⁻¹
Q.20 In an exothermic reaction, ΔH is:
Positive
Negative
Zero
Always increasing
Explanation - Exothermic reactions release heat; enthalpy change ΔH is negative.
Correct answer is: Negative
Q.21 Which factor increases the rate of reaction?
Lower temperature
Decrease in concentration
Catalyst
Inert gas addition
Explanation - Catalysts lower activation energy, thereby increasing the reaction rate without being consumed.
Correct answer is: Catalyst
Q.22 Which solution will have the highest boiling point?
0.1 M NaCl
0.1 M Glucose
0.1 M Urea
Pure water
Explanation - NaCl dissociates into two ions, producing the greatest number of particles and highest elevation in boiling point.
Correct answer is: 0.1 M NaCl
Q.23 Which quantity remains unchanged in an isolated system?
Energy
Mass
Temperature
Volume
Explanation - According to the first law of thermodynamics, energy remains constant in an isolated system.
Correct answer is: Energy
Q.24 Which of the following is used as a standard electrode?
Copper electrode
Hydrogen electrode
Silver electrode
Zinc electrode
Explanation - The standard hydrogen electrode (SHE) is used as the reference electrode with potential defined as zero.
Correct answer is: Hydrogen electrode
Q.25 The order of reaction can be determined by:
Stoichiometry
Experimental data
Balancing equation
Thermodynamic calculations
Explanation - Reaction order is determined experimentally; it cannot always be deduced from stoichiometry.
Correct answer is: Experimental data