4. Which of the following processes will lead to a decrease in the entropy of th
ID: 997949 • Letter: 4
Question
4. Which of the following processes will lead to a decrease in the entropy of the system?
a.
Salt crystals dissolve in water.
b.
Air escapes from a hole in a balloon.
c.
Iron and oxygen react to form rust.
d.
Ice melts in your hand.
e.
None of these lead to a negative change in the entropy of the system, as they are all spontaneous.
5. Which of the relationships A through D between the free energy change of a system and associated entropy changes is true?
a.
DGsys = +T DSsystem
d.
DGsys = –T DSsurroundings
b.
DGsys = –T DSsystem
e.
DGsys = –T DSuniverse
c.
DGsys = +T DSuniverse
6. Which of A–D is a disadvantage in using hydrogen fuel cells instead of gasoline engines in vehicles? If all are valid disadvantages, respond E.
a.
It is difficult to store hydrogen safely.
b.
No distribution network of hydrogen fuel is in place.
c.
Hydrogen fuel must be produced, most likely from water, by using another energy source.
d.
Hydrogen fuel is not really a source of energy, but rather is a way to store energy.
e.
All the above.
7. Which statement regarding voltaic cells is not correct?
a.
Reduction occurs at the cathode.
b.
Anions move through the barrier or bridge toward the electrode where oxidation is occurring.
c.
The electrode where reduction is occurring is represented by a positive sign.
d.
Electrons flow in the external circuit from the cathode to the anode.
e.
Electrons flow in the external circuit toward the electrode represented by a positive sign.
a.
Salt crystals dissolve in water.
b.
Air escapes from a hole in a balloon.
c.
Iron and oxygen react to form rust.
d.
Ice melts in your hand.
e.
None of these lead to a negative change in the entropy of the system, as they are all spontaneous.
Explanation / Answer
answer 4
option e is correct
answer 5
option b
answer 6
It is difficult to store.
Hydrogen is very hard to move around. When speaking about oil, that element can be sent though pipelines. When discussing coal, that can be easily carried off on the back of trucks. When talking about hydrogen, just moving even small amounts is a very expensive matter. For that reason alone, the transport and storage of such a substance is deemed impractical
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.