MCQ Collection
Pakistan MCQs
Practice Pakistan questions with answers and explanations.
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Correct Answer: B. 1.10 V
Explanation:
For standard reduction potentials, E°cell = E°cathode − E°anode.
The positive result indicates a spontaneous standard cell reaction.
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Correct Answer: B. 12000 J
Explanation:
q = mcΔT = 3×500×8.
The required heat is 12000 J.
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Correct Answer: C. 0.46 V
Explanation:
For standard reduction potentials, E°cell = E°cathode − E°anode.
The positive result indicates a spontaneous standard cell reaction.
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Correct Answer: C. -150 kJ mol⁻¹
Explanation:
Hess’s law states that enthalpy changes add for sequential steps.
The overall value is the algebraic sum of the two changes.
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Correct Answer: D. 0.82 V
Explanation:
For standard reduction potentials, E°cell = E°cathode − E°anode.
The positive result indicates a spontaneous standard cell reaction.
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Correct Answer: D. -120 kJ mol⁻¹
Explanation:
Hess’s law states that enthalpy changes add for sequential steps.
The overall value is the algebraic sum of the two changes.
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Correct Answer: A. -150 kJ mol⁻¹
Explanation:
Hess’s law states that enthalpy changes add for sequential steps.
The overall value is the algebraic sum of the two changes.
Choose an option to check your answer.
Correct Answer: B. -50 kJ mol⁻¹
Explanation:
Hess’s law states that enthalpy changes add for sequential steps.
The overall value is the algebraic sum of the two changes.
Choose an option to check your answer.
Correct Answer: C. -150 kJ mol⁻¹
Explanation:
Hess’s law states that enthalpy changes add for sequential steps.
The overall value is the algebraic sum of the two changes.
Choose an option to check your answer.
Correct Answer: D. 300 J
Explanation:
The first law conserves energy: ΔU = q − w for work done by the system.
Substitution gives the stated internal-energy change.
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Correct Answer: A. -200 J
Explanation:
The first law conserves energy: ΔU = q − w for work done by the system.
Substitution gives the stated internal-energy change.
Choose an option to check your answer.
Correct Answer: B. -300 J
Explanation:
The first law conserves energy: ΔU = q − w for work done by the system.
Substitution gives the stated internal-energy change.
