9.4 Free Energy and Equilibrium

Cards (110)

  • In the formula for free energy, H represents the enthalpy
  • A decrease in enthalpy (exothermic) decreases free energy.

    True
  • A positive free energy value indicates a non-spontaneous and unfeasible process.

    True
  • Free energy is denoted by the symbol G
  • What determines the spontaneity of a process in Gibbs free energy?
    Sign of ΔG
  • A negative free energy value indicates a spontaneous process.
    True
  • What determines the spontaneity and feasibility of a chemical process?
    The sign of ΔG
  • A negative ΔG indicates a spontaneous and feasible process.
  • What is the sign of ΔG for the combustion of methane, indicating its spontaneity?
    Negative
  • What does the symbol H represent in the Gibbs free energy equation?
    Enthalpy
  • The formula for free energy (G) is G = H - TS
  • In the free energy formula, T represents the absolute temperature
  • A decrease in enthalpy (exothermic process) decreases free energy
  • A negative free energy value indicates a spontaneous process.
    True
  • What is the formula for calculating Gibbs free energy change (ΔG)?
    ΔG=\Delta G =ΔH−TΔS \Delta H - T\Delta S
  • Match the ΔG values with their corresponding process characteristics:
    ΔG < 0 ↔️ Spontaneous
    ΔG > 0 ↔️ Non-spontaneous
  • Give an example of a chemical reaction with a negative ΔG that is spontaneous at room temperature.
    Combustion of methane
  • What is the definition of the standard free energy change (ΔG°)?
    Free energy change under standard conditions
  • What does the equilibrium constant (K) represent in a chemical reaction?
    Ratio of product to reactant concentrations
  • What is the value of the ideal gas constant (R) in SI units?
    8.314 J/(mol·K)
  • Free energy is defined as G = H - TS
  • A negative free energy value indicates a spontaneous process.

    True
  • The formula for free energy is G = H - TS.

    True
  • An increase in temperature increases the impact of entropy
  • The formula for Gibbs free energy is \Delta G = \Delta H - T\Delta S</latex>
  • In the Gibbs free energy formula, T represents the absolute temperature
  • The Gibbs free energy change (ΔG) is crucial in determining whether a reaction is spontaneous
  • Give an example of a reaction with a negative ΔG that is spontaneous.
    Combustion of methane
  • What is the value of ΔG° for the reaction N_{2}(g) + 3H_{2}(g) \rightarrow 2NH_{3}(g)</latex> at 298 K?
    -32.7 kJ
  • Match the term with its definition:
    ΔH° ↔️ Standard enthalpy change
    ΔS° ↔️ Standard entropy change
    T ↔️ Temperature in Kelvin
  • Match the K value with its interpretation:
    K > 1 ↔️ Reaction favors products
    K < 1 ↔️ Reaction favors reactants
    K = 1 ↔️ Significant concentrations of both
  • For exothermic reactions, higher temperatures make ΔG more negative, enhancing spontaneity.
  • The combustion of methane has a ΔH value that is negative, decreasing the free energy G.
  • The entropy change (ΔS) for the combustion of methane is negative.

    True
  • The entropy change (ΔS) for the decomposition of calcium carbonate is positive.
    True
  • At room temperature, the decomposition of calcium carbonate is non-spontaneous because ΔG is positive
  • At standard conditions, ΔG° for the Haber-Bosch process is -32.7 kJ/mol, indicating the reaction is spontaneous
  • Match the reaction with its properties:
    Combustion of methane ↔️ Exothermic, negative ΔS
    Decomposition of calcium carbonate ↔️ Endothermic, positive ΔS
    Ammonia synthesis ↔️ Negative ΔH, negative ΔS
  • Free energy, denoted as G, is a measure of the spontaneity and feasibility of a chemical process
  • What does T represent in the free energy formula?
    Absolute temperature