Same chapter3 marksDifficulty: Medium
State the relation between Gibbs energy, enthalpy and entropy, and the condition for a spontaneous process.
Chemical Thermodynamics
3 marksDifficulty: Medium
Calculate the enthalpy change of a reaction whose bond enthalpies give 1,200 kJ absorbed to break bonds and 1,500 kJ released to form them.
Original Khojo Papers practice question — not from a past board paper.
Answer
−300 kJ, so the reaction is exothermic.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The enthalpy change is the energy absorbed to break bonds minus the energy released in forming them, 1,200 − 1,500 = −300 kJ.
Related questions
From the same topic and chapter, at a similar level.
Same chapter3 marksDifficulty: Medium
What is entropy, and how does it change when a solid melts and when a gas is compressed?
Chemical Thermodynamics
Same chapter3 marksDifficulty: Medium
Define enthalpy of formation and enthalpy of combustion.
Chemical Thermodynamics
Same chapter3 marksDifficulty: Medium
State Hess's law and give one use of it.
Chemical Thermodynamics
Same chapter3 marksDifficulty: Medium
Distinguish between an open, a closed and an isolated system, with one example of each.
Chemical Thermodynamics
Same subject3 marksDifficulty: Medium
State Hund's rule and the Aufbau principle.
Structure of Atom