Answer: The conversion of natural gas, which is mostly

Chapter , Problem 102AE

(choose chapter or problem)

The conversion of natural gas, which is mostly methane, into products that contain two or more carbon atoms, such as ethane \(\left(C_{2} H_{6}\right)\), is a very important industrial chemical process. In principle, methane can be converted into ethane and hydrogen:

\(2 C H_{4}(g) \rightarrow C_{2} H_{6}(g)+H_{2}(g)\)

In practice, this reaction is carried out in the presence of oxygen:

\(2 C H_{4}(g)+\frac{1}{2} O_{2}(g) \rightarrow C_{2} H_{6}(g)+H_{2} O(g)\)

(a) Using the data in Appendix C, calculate K for these reactions at 25 °C and 500 °C. (b) Is the difference in \(\Delta G^{0}\) for the two reactions due primarily to the enthalpy term \((\Delta H)\) or the entropy term \((-T \Delta S)\)? (c) Explain how the preceding reactions are an example of driving a nonspontaneous reaction, as discussed in the “Chemistry and Life” box in Section 19.7. (d) The reaction of \(\mathrm{CH}_{4}\) and \(O_{2}\) to form \(C_{2} H_{6}\) and \(\mathrm{H}_{2} \mathrm{O}\) must be carried out carefully to avoid a competing reaction. What is the most likely competing reaction?

Equation transcription:

Text transcription:

\left(C_{2} H_{6}\right)

2 C H_{4}(g) \rightarrow C_{2} H_{6}(g)+H_{2}(g)

2 C H_{4}(g)+\frac{1}{2} O_{2}(g) \rightarrow C_{2} H_{6}(g)+H_{2} O(g)

\Delta G^{0}

(\Delta H)

(-T \Delta S)

\mathrm{CH}_{4}

O_{2}

C_{2} H_{6}

\mathrm{H}_{2} \mathrm{O}