What does Gibbs Free Energy tell us?
  • How much energy is given off by a reaction.
  • The tendency of a reaction to become "random"
  • How spontaneous a reaction is.
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.
What are the best conditions to lead towards a spontaneous reaction?
  • high negative enthalpy, high temp, high negative entropy
  • high positive enthalpy, high temp, high negative entropy
  • high negative enthalpy, low temp, high positive entropy
  • high negative enthalpy, high temp, high positive entropy.
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
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
Your enthalpy is +20 and your entropy is +Which temperature will give a spontaneous reaction?
  • 0
  • 4
  • 8
Your enthalpy is -20 and your entropy is -Which temperature will give you a spontaneous reaction?
  • 1
  • 3
  • 5
Which of the following situations demonstrates high entropy?
  • water freezing
  • water vaporizing
  • steam condensing to water
A spontaneous reaction is more profitable to a company.
  • True
  • False
Spontaneous reactions may be extremely slow.
  • True
  • False
A reaction has a positive ΔH and a positive ΔS. Which of the following is true?
  • It will be spontaneous at all temperatures.
  • It will be nonspontaneous at all temperatures.
  • It will be spontaneous at low temperatures.
  • It will be spontaneous at high temperatures.
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
True/False: The rate of a chemical reaction is unrelated to the spontaneity of the reaction.
  • True
  • False
Given the following information, calculate ΔG0 for the reaction below at 250C: (K = 0C + 273)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
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