Home/
Competitive Exams/
JEE Main & Advanced/
Chemistry/
Chemical Thermodynamics and Thermochemistry/
Question 800004
JEE Chemistry · Medium

Chemical Thermodynamics and Thermochemistry: Hess's law MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Hess's lawMediumQuestion 800004

Question

Hess's law states that the enthalpy change for a reaction is:
  1. A
    Independent of the pathway (sum of steps)
    Correct
  2. B
    Equal to activation energy
  3. C
    Always negative
  4. D
    Equal to entropy change

Correct answer

Independent of the pathway (sum of steps)

Explanation

Hess's Law: ΔH for an overall reaction = sum of ΔH values for each step (because H is a state function). It allows calculation of ΔH for reactions that cannot be measured directly.

Review Chemical Thermodynamics and Thermochemistry notesStart timed chapter practice