Concept explainers
A new allotrope of oxygen, O4, has been reported. The exact structure of O4 is unknown, but the simplest possible structure would be a four-member ring consisting of oxygen-oxygen single bonds. The report speculated that the O4 molecule might be useful as a fuel “because it packs a lot of oxygen in a small space, so it might be even more energy-dense than the liquefied ordinary oxygen used in rocket fuel.” (a) Draw a Lewis structure for O4 and write a balanced chemical equation for the reaction between ethane, C2H6(g), and O4(g) to give carbon dioxide and water vapor. (b) Estimate ΔH° for the reaction. (c) Write a chemical equation illustrating the standard enthalpy of formation of O4(g) and estimate ΔH°f. (d) Assuming the oxygen allotropes are in excess, which will release more energy when reacted with ethane (or any other fuel): O2(g) or O4(g)? Explain using your answers to parts (a)–(c).
(a)
Interpretation:
Lewis structure of
Concept Introduction:
Electron dot structure also known as Lewis dot structure represents the number of valence electrons of an atom or constituent atoms bonded in a molecule. Each dot corresponds to one electron.
Balanced reaction is a chemical reaction in which number of atoms for each element in the reaction and the total charge are same on both reactant side and the product side.
Steps in balancing the information
- Step 1: Write the unbalanced equation
- Step 2: Find the coefficient to balance the equation.
According to the “Law of Conservation of Mass”, a chemical equation is balanced when the number of atoms involved in the reactant side is equal to that of the product side.
Explanation of Solution
Total valence electrons in
Accordingly Lewis structure of
Balanced chemical equation for the reaction of
(b)
Interpretation:
Concept Introduction:
Answer to Problem 9.149QP
Explanation of Solution
(c)
Interpretation:
A chemical equation illustrating the reaction of formation of
Concept Introduction:
Answer to Problem 9.149QP
A chemical equation illustrating the reaction of formation of
Explanation of Solution
A chemical equation illustrating the reaction of formation of
Enthalpy of formation of
(d)
Interpretation:
The energy released by reaction of
Answer to Problem 9.149QP
The energy released by reaction of
Explanation of Solution
Hence the energy released by reaction of
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Chapter 9 Solutions
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