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81. According to Raoult's law, the vapour pressure of an ideal solution is directly related to:
- A. The volume of the container
- B. The temperature alone, regardless of composition
- C. The mass of each component in the solution
- D. The mole fraction of each component in the solution
Answer: The mole fraction of each component in the solution
Explanation: The mole fraction of each component in the solution — verified fact for BITSAT Chemistry.
82. What is the mole fraction of solute in a solution containing 2 moles of solute and 8 moles of solvent?
- A. 0.25
- B. 0.2
- C. 2
- D. 0.8
Answer: 0.2
Explanation: 0.2 — verified fact for BITSAT Chemistry.
83. Which of the following is NOT a colligative property?
- A. Relative lowering of vapour pressure
- B. Depression in freezing point
- C. Elevation in boiling point
- D. Colour of the solution
Answer: Colour of the solution
Explanation: Colour of the solution — verified fact for BITSAT Chemistry.
84. What is the molality of a solution prepared by dissolving 5.85 g of NaCl (molar mass 58.5 g/mol) in 500 g of water?
- A. 0.1 mol/kg
- B. 0.2 mol/kg
- C. 0.4 mol/kg
- D. 2 mol/kg
Answer: 0.2 mol/kg
Explanation: 0.2 mol/kg — verified fact for BITSAT Chemistry.
85. What is the SI unit of electrochemical equivalent used in Faraday's laws of electrolysis, expressed in terms of mass per unit charge?
- A. kg/s (kilogram per second)
- B. C/kg (coulomb per kilogram)
- C. kg/C (kilogram per coulomb)
- D. J/C (joule per coulomb)
Answer: kg/C (kilogram per coulomb)
Explanation: kg/C (kilogram per coulomb) — verified fact for BITSAT Chemistry.
86. During the electrolysis of molten NaCl, what is produced at the cathode?
- A. Oxygen gas (O₂)
- B. Chlorine gas (Cl₂)
- C. Hydrogen gas (H₂)
- D. Sodium metal (Na)
Answer: Sodium metal (Na)
Explanation: Sodium metal (Na) — verified fact for BITSAT Chemistry.
87. In the Nernst equation for a cell reaction, as the concentration of the reacting ions changes, what generally happens to the cell potential at non-standard conditions?
- A. The cell potential becomes zero immediately
- B. The cell potential always stays exactly equal to E°
- C. The cell potential becomes infinite
- D. The cell potential deviates from the standard cell potential (E°) depending on the reaction quotient Q
Answer: The cell potential deviates from the standard cell potential (E°) depending on the reaction quotient Q
Explanation: The cell potential deviates from the standard cell potential (E°) depending on the reaction quotient Q — verified fact for BITSAT Chemistry.
88. Which of these metals is the strongest reducing agent based on standard electrode potentials: Na, Cu, Ag, Au?
- A. Na
- B. Ag
- C. Au
- D. Cu
Answer: Na
Explanation: Na — verified fact for BITSAT Chemistry.
89. For a galvanic cell with E°cell = +1.10 V (as in the Daniell cell, Zn/Cu), what can be concluded about the spontaneity of the cell reaction?
- A. No conclusion can be drawn about spontaneity
- B. The reaction is non-spontaneous
- C. The reaction is spontaneous, since ΔG = -nFE°cell is negative
- D. The reaction is at equilibrium
Answer: The reaction is spontaneous, since ΔG = -nFE°cell is negative
Explanation: The reaction is spontaneous, since ΔG = -nFE°cell is negative — verified fact for BITSAT Chemistry.
90. In a galvanic (voltaic) cell, at which electrode does oxidation occur?
- A. Anode
- B. Neither electrode
- C. Cathode
- D. Both electrodes equally
Answer: Anode
Explanation: Anode — verified fact for BITSAT Chemistry.
91. A catalyst increases the rate of a reaction primarily by:
- A. Increasing the enthalpy change of the reaction
- B. Shifting the equilibrium position
- C. Lowering the activation energy of the reaction
- D. Increasing the temperature of the reaction mixture
Answer: Lowering the activation energy of the reaction
Explanation: Lowering the activation energy of the reaction — verified fact for BITSAT Chemistry.
92. What is the order of a reaction whose rate law is Rate = k[A]²[B]?
- A. 2 (second order overall)
- B. 3 (third order overall)
- C. 1 (first order overall)
- D. 5 (fifth order overall)
Answer: 3 (third order overall)
Explanation: 3 (third order overall) — verified fact for BITSAT Chemistry.
93. According to the Arrhenius equation, increasing the temperature of a reaction generally causes the rate constant to:
- A. Become zero
- B. Increase
- C. Remain unchanged
- D. Decrease
Answer: Increase
Explanation: Increase — verified fact for BITSAT Chemistry.
94. What are the units of the rate constant k for a second-order reaction (concentration in mol/L, time in seconds)?
- A. mol L⁻¹ s⁻¹
- B. mol² L⁻² s⁻¹
- C. s⁻¹
- D. L mol⁻¹ s⁻¹
Answer: L mol⁻¹ s⁻¹
Explanation: L mol⁻¹ s⁻¹ — verified fact for BITSAT Chemistry.
95. For a zero-order reaction, how does the rate of reaction depend on the concentration of the reactant?
- A. The rate is independent of the concentration of the reactant
- B. The rate is directly proportional to the concentration
- C. The rate is inversely proportional to the concentration
- D. The rate is proportional to the square of the concentration
Answer: The rate is independent of the concentration of the reactant
Explanation: The rate is independent of the concentration of the reactant — verified fact for BITSAT Chemistry.
96. A first-order reaction has a rate constant of 0.0231 min⁻¹. What is its half-life (using t½ = 0.693/k)?
- A. 15 minutes
- B. 30 minutes
- C. 23.1 minutes
- D. 60 minutes
Answer: 30 minutes
Explanation: 30 minutes — verified fact for BITSAT Chemistry.
97. A large value of the equilibrium constant K (K >> 1) indicates that at equilibrium:
- A. Products are favoured over reactants
- B. The reaction has not started
- C. The reaction is at 50% completion
- D. Reactants are favoured over products
Answer: Products are favoured over reactants
Explanation: Products are favoured over reactants — verified fact for BITSAT Chemistry.
98. Adding an inert gas at constant volume to a system at equilibrium will:
- A. Double the equilibrium constant
- B. Not shift the equilibrium (partial pressures of reactants/products unchanged)
- C. Shift the equilibrium backward
- D. Shift the equilibrium forward
Answer: Not shift the equilibrium (partial pressures of reactants/products unchanged)
Explanation: Not shift the equilibrium (partial pressures of reactants/products unchanged) — verified fact for BITSAT Chemistry.
99. What is the relationship between Kp and Kc for a reaction at temperature T, where Δn is the change in moles of gas (Kp = Kc(RT)^Δn)? For N₂O₄(g) ⇌ 2NO₂(g), what is Δn?
- A. Δn = -1
- B. Δn = 1
- C. Δn = 0
- D. Δn = 2
Answer: Δn = 1
Explanation: Δn = 1 — verified fact for BITSAT Chemistry.
100. For an exothermic reaction at equilibrium, what happens if the temperature is increased (Le Chatelier's principle)?
- A. No change occurs
- B. Equilibrium constant becomes infinite
- C. Equilibrium shifts forward, favouring the products
- D. Equilibrium shifts backward, favouring the reactants
Answer: Equilibrium shifts backward, favouring the reactants
Explanation: Equilibrium shifts backward, favouring the reactants — verified fact for BITSAT Chemistry.
101. For the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g), what happens to the equilibrium position if the pressure is increased (Le Chatelier's principle)?
- A. The reaction stops entirely
- B. Equilibrium shifts toward the side with fewer gas moles (forward, toward NH₃)
- C. Equilibrium is unaffected by pressure
- D. Equilibrium shifts backward toward N₂ and H₂
Answer: Equilibrium shifts toward the side with fewer gas moles (forward, toward NH₃)
Explanation: Equilibrium shifts toward the side with fewer gas moles (forward, toward NH₃) — verified fact for BITSAT Chemistry.
102. According to the first law of thermodynamics, energy of an isolated system:
- A. Always increases
- B. Becomes zero
- C. Always decreases
- D. Remains constant
Answer: Remains constant
Explanation: Remains constant — verified fact for BITSAT Chemistry.
103. A process with ΔS(universe) > 0 is best described as:
- A. Impossible
- B. At equilibrium
- C. Spontaneous
- D. Non-spontaneous
Answer: Spontaneous
Explanation: Spontaneous — verified fact for BITSAT Chemistry.
104. Which thermodynamic function is used to predict spontaneity of a reaction at constant temperature and pressure?
- A. Enthalpy (H)
- B. Internal energy (U)
- C. Work done (w)
- D. Gibbs free energy (G)
Answer: Gibbs free energy (G)
Explanation: Gibbs free energy (G) — verified fact for BITSAT Chemistry.
105. What is the standard enthalpy of formation of an element in its most stable standard state?
- A. Zero
- B. One
- C. Infinite
- D. Negative
Answer: Zero
Explanation: Zero — verified fact for BITSAT Chemistry.
106. If ΔH = 100 kJ/mol and ΔS = 200 J K⁻¹ mol⁻¹ for a reaction at 400 K, what is ΔG (using ΔG = ΔH - TΔS)?
- A. 20 kJ/mol
- B. 180 kJ/mol
- C. 100 kJ/mol
- D. -20 kJ/mol
Answer: 20 kJ/mol
Explanation: 20 kJ/mol — verified fact for BITSAT Chemistry.
107. For a reaction to be spontaneous at all temperatures, what must be true of ΔH and ΔS?
- A. Both ΔH and ΔS are positive
- B. ΔH is positive and ΔS is negative
- C. ΔH is negative and ΔS is positive
- D. Both ΔH and ΔS are negative
Answer: ΔH is negative and ΔS is positive
Explanation: ΔH is negative and ΔS is positive — verified fact for BITSAT Chemistry.
108. For a reaction at constant pressure, which thermodynamic quantity equals the heat exchanged with the surroundings?
- A. Entropy change (ΔS)
- B. Internal energy change (ΔU)
- C. Enthalpy change (ΔH)
- D. Gibbs free energy change (ΔG)
Answer: Enthalpy change (ΔH)
Explanation: Enthalpy change (ΔH) — verified fact for BITSAT Chemistry.
109. A coordinate (dative) covalent bond is best described as one where:
- A. No electrons are shared between the atoms
- B. Both shared electrons of the bond come from the same atom
- C. Each atom contributes one electron to the shared pair
- D. Electrons are completely transferred from one atom to another
Answer: Both shared electrons of the bond come from the same atom
Explanation: Both shared electrons of the bond come from the same atom — verified fact for BITSAT Chemistry.
110. What is the bond order of the nitrogen molecule (N₂) according to molecular orbital theory?
- A. 2.5
- B. 2
- C. 1
- D. 3
Answer: 3
Explanation: 3 — verified fact for BITSAT Chemistry.
111. Which of these molecules has zero net dipole moment despite having polar bonds: CO₂ or H₂O?
- A. Both have zero dipole moment
- B. H₂O
- C. Neither has zero dipole moment
- D. CO₂
Answer: CO₂
Explanation: CO₂ — verified fact for BITSAT Chemistry.
112. What is the shape of the water (H₂O) molecule?
- A. Tetrahedral
- B. Trigonal planar
- C. Bent (angular)
- D. Linear
Answer: Bent (angular)
Explanation: Bent (angular) — verified fact for BITSAT Chemistry.
113. Which type of bond is formed by the complete transfer of electrons from one atom to another?
- A. Ionic bond
- B. Coordinate bond
- C. Metallic bond
- D. Covalent bond
Answer: Ionic bond
Explanation: Ionic bond — verified fact for BITSAT Chemistry.
114. What is the hybridisation of the carbon atom in ethyne (C₂H₂)?
- A. sp
- B. sp³
- C. sp²
- D. sp³d
Answer: sp
Explanation: sp — verified fact for BITSAT Chemistry.
115. What is the shape of the CH₄ molecule according to VSEPR theory?
- A. Square planar
- B. Linear
- C. Tetrahedral
- D. Trigonal planar
Answer: Tetrahedral
Explanation: Tetrahedral — verified fact for BITSAT Chemistry.
116. How many orbitals are present in a d-subshell?
- A. 5
- B. 3
- C. 1
- D. 7
Answer: 5
Explanation: 5 — verified fact for BITSAT Chemistry.
117. What is the shape of a p-orbital?
- A. Dumbbell-shaped
- B. Doughnut-shaped
- C. Spherical
- D. Double dumbbell (cloverleaf)
Answer: Dumbbell-shaped
Explanation: Dumbbell-shaped — verified fact for BITSAT Chemistry.
118. Which principle states that no two electrons in an atom can have the same set of all four quantum numbers?
- A. Pauli's exclusion principle
- B. Hund's rule
- C. Heisenberg's uncertainty principle
- D. Aufbau principle
Answer: Pauli's exclusion principle
Explanation: Pauli's exclusion principle — verified fact for BITSAT Chemistry.
119. According to Hund's rule, how do electrons fill degenerate orbitals of the same subshell?
- A. Two at a time with opposite spins from the start
- B. Randomly, with no preference for spin
- C. Singly into each orbital first, with parallel spins, before pairing
- D. Paired into one orbital first before occupying others
Answer: Singly into each orbital first, with parallel spins, before pairing
Explanation: Singly into each orbital first, with parallel spins, before pairing — verified fact for BITSAT Chemistry.
120. What is the electronic configuration of the chromium (Cr, Z = 24) atom in its ground state?
- A. [Ar] 3d⁶ 4s⁰
- B. [Ar] 4s² 3d⁴
- C. [Ar] 3d⁴ 4s²
- D. [Ar] 3d⁵ 4s¹
Answer: [Ar] 3d⁵ 4s¹
Explanation: [Ar] 3d⁵ 4s¹ — verified fact for BITSAT Chemistry.
121. What is the maximum number of electrons that can be accommodated in the n = 3 shell?
- A. 8
- B. 18
- C. 9
- D. 32
Answer: 18
Explanation: 18 — verified fact for BITSAT Chemistry.
122. Which quantum number specifies the orientation of an atomic orbital in space?
- A. Principal quantum number (n)
- B. Magnetic quantum number (m)
- C. Spin quantum number (s)
- D. Azimuthal quantum number (l)
Answer: Magnetic quantum number (m)
Explanation: Magnetic quantum number (m) — verified fact for BITSAT Chemistry.
123. Real gases deviate most from ideal behaviour under which conditions?
- A. High pressure and high temperature
- B. Low pressure and high temperature
- C. High pressure and low temperature
- D. Low pressure and low temperature
Answer: High pressure and low temperature
Explanation: High pressure and low temperature — verified fact for BITSAT Chemistry.
124. At STP (0°C, 1 atm), what is the molar volume of an ideal gas?
- A. 1 L/mol
- B. 22.4 L/mol
- C. 11.2 L/mol
- D. 24.4 L/mol
Answer: 22.4 L/mol
Explanation: 22.4 L/mol — verified fact for BITSAT Chemistry.
125. Which law states that at constant temperature, the volume of a fixed amount of gas is inversely proportional to its pressure?
- A. Charles's law
- B. Avogadro's law
- C. Gay-Lussac's law
- D. Boyle's law
Answer: Boyle's law
Explanation: Boyle's law — verified fact for BITSAT Chemistry.
126. What is the value of the universal gas constant R in SI units (approximately)?
- A. 0.0821 J K⁻¹ mol⁻¹
- B. 1.987 J K⁻¹ mol⁻¹
- C. 8.314 J K⁻¹ mol⁻¹
- D. 22.4 J K⁻¹ mol⁻¹
Answer: 8.314 J K⁻¹ mol⁻¹
Explanation: 8.314 J K⁻¹ mol⁻¹ — verified fact for BITSAT Chemistry.
127. According to the kinetic theory of gases, at a given temperature, which gas molecules have the highest average speed?
- A. The heaviest gas (highest molar mass)
- B. The lightest gas (lowest molar mass)
- C. It depends only on pressure, not molar mass
- D. All gases have the same average speed
Answer: The lightest gas (lowest molar mass)
Explanation: The lightest gas (lowest molar mass) — verified fact for BITSAT Chemistry.
128. A gas occupies 2 L at 1 atm and 300 K. What is its volume at 2 atm and 300 K (ideal gas, constant temperature)?
- A. 1 L
- B. 2 L
- C. 0.5 L
- D. 4 L
Answer: 1 L
Explanation: 1 L — verified fact for BITSAT Chemistry.
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