If a chemical change takes place by several different routes, the overall energy change is the same, regardless of the route by which the chemical change occurs provided the initial and final conditions are the same. This is in accordance to:
Correct answer: B. Hess's Law
- A. Law of mass action
- B. Hess's Law
- C. Joule's Law
- D. First law of thermodynamics
Explanation
This statement is related to Hess's law which states that: "If a chemical change takes place by several different routes, the overall energy change is the same, regardless of the route by which the chemical change occurs provided the initial and final conditions are the same." Hess's Law is particularly useful when experimental measurements of enthalpy changes are challenging, as it allows us to calculate the enthalpy change indirectly by combining known enthalpy changes for other reactions. This law is often used in thermochemistry and is essential for the calculation of standard enthalpy of formation values and for understanding and predicting the energy changes associated with chemical reactions.
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About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
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