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WorksheetsAP Chemistry Gibbs Free Energy and Equilibrium Constants
Total questions: 22
Worksheet time: 21mins
What does Gibbs Free Energy tell us?
How much energy is given off by a reaction.
The tendency of a reaction to become "random"
The feasibility of a reaction.
The degree of disorder
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 large negative enthalpy.
A small negative enthalpy.
A large positive enthalpy.
A small positive enthalpy.
A reaction has a positive ΔH and a positive ΔS. Which of the following is likely?
It will be spontaneous at all temperatures.
The reaction is never feasible.
It will be spontaneous at low temperatures.
It will be spontaneous at high temperatures.
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
Feasible at all temperatures
Never feasible
Your enthalpy is positive and your entropy is positive. What type of temperature would you want to ensure a spontaneous reaction.
very high
very low
Which combination of ΔH and ΔS NEVER has a spontaneous reaction?
+ΔH and +ΔS
+ΔH and -ΔS
-ΔH and -ΔS
-ΔH and +ΔS
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
For the process at 250C : I2(g) →I2(s). What are the signs for ΔG, ΔH and ΔS?
ΔG + ΔH - ΔS -
ΔG - ΔH - ΔS -
ΔG - ΔH + ΔS +
ΔG - ΔH + ΔS +
Predict the signs of ΔH , ΔS and ΔG for the reaction:
Mg(s) --> Mg(g)
Δ H = - , Δ S = + and Δ G = - (all temperature)
Δ H = + , Δ S = + and Δ G = - (At all temperature)
Δ H = + , Δ S = + and Δ G = - (At low temperature)
Δ H = + , Δ S = + and Δ G = - (At high temperature)
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
The rate of a chemical reaction is unrelated to the spontaneity of the reaction.
True
False
A positive ΔG is...
Feasible
Not feasible
A reaction will be feasible at all temperatures if its has
Positive enthalpy, positive entropy
Negative enthalpy, positive entropy
Negative enthalpy, negative entropy
Positive enthalpy, negative entropy
What value is Gibbs free energy at the boiling point of water?
0
273
100
-273
To convert Celsius to kelvin you must-
-273
+273
/1000
x1000
Calculate the standard entropy change for the following reaction: Cu(s)+1/2 O2(g) → CuO(s). Given that
S0 (Cu(s)) = 33.15 J/K*mol
S0 (O2(g)) = 205.14 J/K*mol
S0 (CuO(s)) = 42.5 J/K*mol
195.66 J/K.mol
93.09 J/K.mol
-93.09 J/K.mol
+195.66 J/K.mol
Given the following information, calculate ΔG0 for the reaction below at 250C:
SnCl4(l) + 2 H20(l) → SnO2(S) + 4HCl(g),
ΔH0=133.0 kJ and ΔS0 =401.5 J/K
-252.6 kJ
-13.4 kJ
13.4 kJ
252.6 kJ
If a process is exothermic and not spontaneous, then what must be true?
ΔS > 0
ΔH > 0
ΔG = 0
ΔS < 0
I feel I am understanding the concept of Gibbs free energy...
Strong agree
Agree
Not really
Help!
