Practice Enthalpy Change, ∆rh Of A Reaction – Reaction Enthalpy (5.4) - Thermodynamics

Practice: Enthalpy change, ∆rH of a reaction – Reaction Enthalpy

Lesson 5.4Thermodynamics

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9 questions

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6 sample questions

Question 1.
What is the formula for calculating reaction enthalpy?
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Think about the relationship between products and reactants.
Question 2.
Explain what Hess's Law states.
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Consider it like a shortcut to finding enthalpy for complex reactions.
3Question 3.
Which of the following defines enthalpy change (∆rH)?
- A measure of heat absorbed during a reaction.
- The sum of all products formed.
- The energy required to initiate a reaction.
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Consider which option references heat specifically.
4Question 4.
True or False: Hess's Law allows us to determine enthalpy changes for reactions that cannot be measured directly.
- True
- False
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Does it state you can only measure directly?
Question 5.
Calculate the reaction enthalpy for the combustion of butane given: ∆Hf°(C4H10) = -125.6 kJ/mol, ∆Hf°(CO2) = -393.5 kJ/mol, ∆Hf°(H2O) = -285.8 kJ/mol. The reaction is C4H10 + 13/2 O2 → 4CO2 + 5H2O.
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Consider the stoichiometric coefficients in your calculations.
Question 6.
Explain how the enthalpy change differs between a reaction done at high versus low temperature, specifically in relation to spontaneity.
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Think about how temperature influences movement.

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