Explanation The given reaction is: H 2 ( g ) + 1 2 O 2 ( g ) → H 2 O ( g ) In the reactant, we need to break one H – H bond and half of O – O bond to form two O – H bonds, therefore we have Δ H rxn = ∑ Δ H reactants ( bonds broken ) + ∑ Δ H rproducts ( bonds formed ) = ∑ Δ H ( H-H ) + 1 2 Δ H ( O=O ) + ∑ 2 Δ H ( O-H ) ∑ Δ H reactants ( bonds broken ) = 436 + 1 2 × 498 = 685 kJ/mol ∑ Δ H rproducts ( bonds formed ) = 2 × ( − 464 ) = − 928 kJ/mol , Hence we get, Δ H rxn = ∑ Δ H reactants ( bonds broken ) + ∑ Δ H rproducts ( bonds formed ) = 685 − 948 = − 243 kJ/mol This is the energy released per mol. The energy released per gram of hydrogen is calculated by dividing the energy released per mol by atomic mass of hydrogen. E n e r g y r e l e a s e d p e r g r a m = − 243 kJ/mol 2.016 g / m o l = − 121

Chemistry: A Molecular Approach Plus Mastering Chemistry with Pearson eText -- Access Card Package (4th Edition) (New Chemistry Titles from Niva Tro)

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ISBN: 9780134103976

Author: Nivaldo J. Tro

Publisher: PEARSON

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Chapter 9, Problem 105E

Interpretation Introduction

To calculate: ΔHrxn for the reaction

H2(g)+12O2(g)→H2O(g)

and also for the combustion of methane (CH4) in kJ/mol and kJ/g. Identify which fuel released more energy.

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Chapter 9, Problem 104E

Chapter 9, Problem 106E

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Chapter 9 Solutions

Chemistry: A Molecular Approach Plus Mastering Chemistry with Pearson eText -- Access Card Package (4th Edition) (New Chemistry Titles from Niva Tro)

Ch. 9 - Prob. 1SAQ Ch. 9 - Q2. Which set of elements is arranged in order of...Ch. 9 - Q3. Which is the correct Lewis structure for...Ch. 9 - Q4. Which compound is likely to have an incomplete...Ch. 9 - Prob. 5SAQ Ch. 9 - Prob. 6SAQ Ch. 9 - Prob. 7SAQ Ch. 9 - Prob. 8SAQ Ch. 9 - Prob. 9SAQ Ch. 9 - Prob. 10SAQ

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Δ H r x n for the reaction H 2 ( g ) + 1 2 O 2 ( g ) → H 2 O ( g ) and also for the combustion of methane ( C H 4 ) in k J / m o l and k J / g . Identify which fuel released more energy.

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To calculate: ΔHrxn for the reaction H2(g)+12O2(g)→H2O(g) and also for the combustion of methane (CH4) in kJ/mol and kJ/g. Identify which fuel released more energy.

Want to see the full answer?

Chapter 9 Solutions

To calculate: ΔHrxn for the reaction

H2(g)+12O2(g)→H2O(g)

and also for the combustion of methane (CH4) in kJ/mol and kJ/g. Identify which fuel released more energy.