Practice Problem 4: Hess’s Law With Formation Enthalpies (4.4) - Unit 5: Energetics and Thermochemistry

Practice: Problem 4: Hess’s Law with Formation Enthalpies

Lesson 4.4Unit 5: Energetics and Thermochemistry

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9 questions

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6 sample questions

Question 1.
What does Hess's Law state?
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Consider how reaction energy is viewed as a state function.
Question 2.
Define Standard Enthalpy of Formation.
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Think about how products are formed from reactants.
3Question 3.
What is Hess's Law?
- A law regarding entropy changes.
- A principle stating that total enthalpy change is independent of steps taken.
- A method for measuring heat directly.
- A concept that applies only to exothermic reactions.
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Think about how energy is conserved in chemical processes.
4Question 4.
When is the standard enthalpy of formation of an element zero?
- True
- False
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Refer to the definition of formation enthalpy.
Question 5.
Using Hess's Law, calculate the enthalpy change of forming NH₄Cl(s) from nitrogen, hydrogen, and chlorine. Given ΔH_f° for NH₄Cl(s), N₂(g), H₂(g), and Cl₂(g).
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Make sure to check if you need to reverse any equations!
Question 6.
How would varying pressures and temperatures affect your calculations of ΔH using Hess's law?
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Reflect on how enthalpy is dependent on the conditions.

5 more questions in this section. Enroll free to practise them all.