Three of the forms of elemental carbon are graphite, diamond,
and buckminsterfullerene. The entropies at 298 K
for graphite and diamond are listed in Appendix C.
(b) What would you expect for the S° value of buckminsterfullerene
(Figure 12.49, p. 509) relative to the values
for graphite and diamond? Explain.

Question

Accepted Answer

welcome everyone. We have diamond, graphite and filtering as elemental forms of carbon. If the entropy for carbon ak diamond is 2.43 jewels per moles times kelvin and the standard entropy for carbon and graphite form is 5. joules per mole times kelvin, which statement is correct regarding the value of standard entropy for carbon 20 fuel marine based on the standard entropy of diamond and graphite. And we need to explain. So they give us our molecule of fuel or in here. So this is what we want to recall is what fuel urine looks like defined by the formula C 20 in this case at least because it can have multiple different formulas of carbon. So we want to recognize that our molecule of filtering is defined as having a high amount of translational freedom, meaning that this structure can move around freely. We also want to recognize based on this image that we have a lot of empty space that we see making up this entire structure of fuel a ring. So we have a high amount of empty space, even more so than our diamond and graphite forms of carbon. We also want to next recognize that the 20 carbon atoms that make up our fuel urine will occupy a large volume so occupy a significantly large and lastly we want to recognize that fuel during has a lot of flexibility as we can see in our image here. So we'll say high flexibility And this would be a higher degree of flexibility than we would see in sheets of graphite or in diamond. So going back to the fact that we stated that fuel or in carbon 20 have atoms that occupy a significantly large volume more so than carbon in graphite form and in diamond form, we would confirm that this corresponds to a will say therefore Carbon Fuel during has an absolute entropy that is greater than diamond and graphite. So going down to our answer choices, we would confirm that the only correct choice to complete this example is going to be choice C, which states that carbon 20 fuel Aaron will have a greater standard entropy than the standard entropy of graphite because it occupies a larger volume than diamond and graphite. So, C is our final answer. I hope everything I reviewed was clear. If you have any questions, please leave them down below and I'll see everyone in the next practice video.

Verified Solution

Key Concepts

Entropy (S°)

Allotropes of Carbon

Comparative Entropy of Allotropes