Question
Identify the law for the statement "Overall the enthalpy change for a reaction is equal to sum of enthalpy changes of individual steps in the reaction"
MHT CET
Chemistry
Thermodynamics (C)
2026
MHT CET 2026 (20 April Shift 1)
MHT CET Chemistry Question (2026) — Solution
Options
- A. First law of thermodynamics
- B. Hess's law
- C. Avogadro's law
- D. Second law of thermodynamics
Answer
B. Hess's law
Step-by-step solution
Hess's law of constant heat summation states that the total enthalpy change for a chemical reaction is independent of the path by which the reaction occurs. If a reaction takes place in several steps, the overall enthalpy change is equal to the sum of the enthalpy changes of the individual steps. This is because enthalpy is a state function, meaning it depends only on the initial and final states of the system, not on the path taken. Answer: Hess's law
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