WorksheetsEntropy
Total questions: 15
Worksheet time: 14mins
Which of these processes represents a decrease in entropy?
sublimation of CO2
boiling water
condensation of steam on cold glass
NaCl dissolving in water
Which of these reactions shows a DECREASE in entropy?
CaCO3(s) → CaO(s) + CO2(g)
3O2(g) → 2O3(g)
2NH3(g) → 3H2(g) + N2(g)
C6H6(l) → C6H6(g)
Which reaction has a +ΔS ?
AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
H2O(g) + CO2(g) → H2CO3(aq)
H2(g) + I2(g) → 2Hl(g)
C2H2O2(g) → 2CO(g) + H2(g)
Systems in nature tend to undergo changes toward
lower energy and less disorder
lower energy and more disorder
higher energy and less disorder
higher energy and more disorder
What is a spontaneous process ?
slow process
fast process
process that needs an external intervention to occur
process that does not need external intervention to occur / keep happening
What information do we need to perform a calculation of Gibbs Free Energy?
Enthalpy of the reaction.
Entropy of the reaction.
The temperature of the reaction in Kelvin.
All of the above are needed.
Which of the following would most likely lead to a spontaneous reaction.
A high negative enthalpy.
A low negative enthalpy.
A high positive enthalpy.
A low positive enthalpy.
Your enthalpy is +20 and your entropy is +5. Which temperature will give a spontaneous reaction?
0
4
8
Your enthalpy is high and negative but your entropy is also negative. What type of temperature would you want to get a spontaneous reaction?
low
high
Which combination of ΔH and ΔS NEVER has a spontaneous reaction?
+ΔH and +ΔS
+ΔH and -ΔS
-ΔH and -ΔS
-ΔH and +ΔS
Your enthalpy is -20 and your entropy is -8. Which temperature will give you a spontaneous reaction?
1
3
5
At what temperature would a given reaction become spontaneous if ΔH =+119kJ and ΔS=+263J/K.mol
452 K
-2210 K
382 K
-363 K
6. The formation ½ A2 + 2 B2 + C --> CAB4 has an enthalpy of formation of -104 kJ and a change in entropy of -60.8 J/K at 30 °C. What is the free energy and spontaneity of the reaction?
-85.6 kJ, spontaneous
-18.3 kJ, not spontaneous
+18.3 kJ, spontaneous
+85.6 kJ, not spontaneous
