2.2 - Hess’s Law: Enthalpy Is Path-Independent
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Practice Questions
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Define Hess's Law.
💡 Hint: Think about how the overall energy change is concerned with initial and final states.
Explain the significance of Hess’s Law in thermochemistry.
💡 Hint: Consider how we can break down complex reactions into simpler parts.
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Interactive Quizzes
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What does Hess's Law state?
💡 Hint: Focus on how the reaction can occur in different manners.
True or False: Hess’s Law allows us to calculate unknown enthalpy changes.
💡 Hint: Consider how complex reactions can be approached.
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Challenge Problems
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Given the standard enthalpy of formation values for N₂(g)=0, O₂(g)=0, and ΔH_f°[NO(g)] = 90.3 kJ/mol, calculate ΔH for the reaction: N₂(g) + O₂(g) → 2NO(g).
💡 Hint: Remember that formation enthalpy values for elements in their standards states are zero.
Using Hess's Law, if the enthalpy change for the combustion of propane (C3H8) is -2043 kJ/mol, derive the enthalpy change for the formation of propane.
💡 Hint: Think about how reversing a reaction changes the sign of ΔH.
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