Which change will not decrease the entropy of a system?
Changing state from gas to liquid
Decreasing the temperature
A reaction where two moles of gaseous reactants changes to four moles of gaseous products
Reducing the volume of the container for a gaseous reaction
When solid ammonium chloride dissolves in distilled water, the temperature of the solution decreases.
What are the signs of ΔHϴ , ΔSϴ , and ΔGϴ for this spontaneous process?
| ΔHϴ | ΔSϴ | ΔGϴ | |
| A. | - | - | - |
| B. | + | + | + |
| C. | + | + | - |
| D. | + | - | + |
A reaction has a standard entropy change, ΔSΘ of +10.00 J K-1 mol-1. The same reaction has a standard enthalpy change, ΔHΘ, of +10.00 kJ mol-1.
Which of the following is used to calculate the value of ΔGΘ for the reaction in kJ mol-1?
10 - (298 x 0.001)
10 - (298 x 0.01)
10 - (298 x 10)
0.01 - (298 x 10)
Propane is produced by the hydrogenation of propene.
| Formula | S Θ / J K-1 mol-1 |
| H2 (g) | +131 |
| C3H6 (g) | +267 |
| C3H8 (g) | +270 |
Which of the following is the correct calculation to determine the entropy change, ΔS Θ, for the reaction?
(267 +131) - 270
270 + (267 +131)
(-270) - (267 +131)
270 - (267 + 131)
Which species are arranged in order of decreasing entropy?
C2H6 (g) > C2H5OH (l) > Hg (l) > Mg (s)
C2H5OH (l) > C2H6 (g) > Hg (l) > Mg (s)
Mg (s) > C2H5OH (l) > Hg (l) > C2H6 (g)
Mg (s) > Hg (l) > C2H6 (g) > C2H5OH (l)
