Chapter 18 Reaction Rates And Equilibrium Part 2 3/13/11

24 Questions | Total Attempts: 39

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Chemistry Quizzes & Trivia

Chapter 18 Reaction Rates and Equilibrium Part 2 3/13/11


Questions and Answers
  • 1. 
    Does entropy tend to increase or decrease in chemical reactions in which the total number of product molecules is greater than the total number of reactant molecules? ______________________
    • A. 

      Entropy decreases

    • B. 

      Entropy increases

    • C. 

      Entropy stays the same

  • 2. 
    Entropy tends to ______________________ when temperature increases.
    • A. 

      Increase

    • B. 

      Decrease

    • C. 

      Stay the same

  • 3. 
    What determines whether a reaction is spontaneous?
    • A. 

      The size and direction of heat (enthalpy) changes and entropy changes together determine whether a reaction is spontaneous.

    • B. 

      The size and direction of moisture(enthalpy) changes and entropy changes together determine whether a reaction is spontaneous.

    • C. 

      The size and amount of heat (enthalpy) changes and entropy changes together determine whether a reaction is spontaneous.

  • 4. 
    Why is an exothermic reaction accompanied by an increase in entropy considered a spontaneous reaction?
    • A. 

      Because both factors are favorable too many

    • B. 

      Because both factors are not favorable

    • C. 

      Because both factors are favorable

  • 5. 
    A nonspontaneous reaction, one in which the products are __________, has heat changes, entropy changes, or both working against it.
    • A. 

      Not favored

    • B. 

      Favored

    • C. 

      Small

  • 6. 
    What is the symbol for entropy and what are the units?
    • A. 

      J; P/S

    • B. 

      R; J/P

    • C. 

      S; J/K

  • 7. 
    The standard entropy of a liquid or solid substance at 25 °C is designated as ______________________ .
    • A. 

      S exponent 0

    • B. 

      S exponent 9

    • C. 

      S exponent 4

  • 8. 
    What is the pressure at S exponent 0 for gaseous substances?
    • A. 

      101.9 kPa

    • B. 

      101.3 kPa

    • C. 

      101.6 kPa

  • 9. 
    The theoretical entropy of a perfect crystal at 0 K is ____________.
    • A. 

      -0

    • B. 

      4

    • C. 

      0

  • 10. 
    What is the equation used to calculate standard entropy change (triangleS exponent 0)?
    • A. 

      ΔS0 =S exponent 1 (products) - S exponent -1 (reactants)

    • B. 

      ΔS0 =S exponent 0 (products) - S exponent -0 (reactants)

    • C. 

      ΔS0 =S exponent 0 (products) - S exponent 0 (reactants)

  • 11. 
    What is the standard entropy of calcium carbonate (CaCO3)?
    • A. 

      98.7 J/Kmol

    • B. 

      88.7 J/Kmol

    • C. 

      108.7 J/Kmol

  • 12. 
    The Gibbs free-energy change (ΔG) is the maximum amount of energy that can be coupled to another process to do useful
    • A. 

      Work

    • B. 

      Rest

    • C. 

      Product

  • 13. 
    What is the equation used to calculate the Gibbs free-energy change?
    • A. 

      ΔG = ΔH =TΔS, where ΔH is the change in enthalpy, ΔS is the change in entropy, and temperature (T) is in kelvins.

    • B. 

      ΔG = ΔH =TΔS, where ΔH is the no change in enthalpy, ΔS is the change in entropy, and temperature (T) is in kelvins.

    • C. 

      ΔG = ΔH =TΔS, where ΔH is the small change in enthalpy, ΔS is the change in entropy, and temperature (T) is in kelvins.

  • 14. 
    The numerical value of ΔG is _____________________ in spontaneous processes because the system loses free energy; the numerical value of ΔG is _____________________ in nonspontaneous processes because the system requires that work be expended to make them go forward at the specified conditions.
    • A. 

      Negative, positive

    • B. 

      Positive, negative

    • C. 

      Both negative, positive and positive, negative

  • 15. 
    What is the equation used to calculate the standard free-energy change (ΔG exponent 0) of a  chemical reaction?
    • A. 

      ΔGexponent0 = ΔH exponent 0=TΔS0, where ΔH exponent 0 and ΔS exponent 0 are known, and the temperature (T) is in kelvins.

    • B. 

      ΔG exponent 0 = ΔHexponent0=TΔSexponent 0, where ΔHexponent 0 and ΔSexponent 0 are unknown, and the temperature (T) is in kelvins.

    • C. 

      ΔG exponent 0 = ΔH exponent 0=TΔS exponent 0, where ΔH exponent 0 and ΔS exponent 0 are known, and the temperature (T) is in kelvins.

  • 16. 
    How do you calculate the standard free-energy change (ΔG exponent 0) of a chemical reaction when ΔH exponent 0 and ΔS exponent 0 are unknown?
    • A. 

      You use ΔG exponent 0 f , the standard free-energy change for the formation of substances from their elements. The formula is ΔG0 = ΔG exponet 0 f (products) = ΔG exponent0 f (reactants).

    • B. 

      You use ΔG exponent 0 f , the standard free-energy no change for the formation of substances from their elements. The formula is ΔG0 = ΔG exponet 0 f (products) = ΔG exponent0 f (reactants).

    • C. 

      You use ΔG exponent 0 t , the standard free-energy no change for the formation of substances from their elements. The formula is ΔG0 = ΔG exponet 0 f (products) = ΔG exponent0 f (reactants).

  • 17. 
    What is a one-step reaction?
    • A. 

      It is a reaction with ore than one activated complex between the reactants and the products.

    • B. 

      It is a reaction with only one activated complex between the reactants and the products.

    • C. 

      It is a reaction with only one activated complex between the reactants and the heat.

  • 18. 
    What is a specific rate constant (k) for a reaction?
    • A. 

      The constant is a proportionality constant relating the concentrations of chemical change to the rate of the reaction.

    • B. 

      The constant is a proportionality constant relating the concentrations of reactants to the rate of the reaction.

    • C. 

      The constant is a proportionality constant relating the concentrations of product to the rate of the reaction.

  • 19. 
    The ______________________ of a reaction is the power to which the concentration of a reactant must be raised to give the experimentally observed relationship between concentration and rate.
    • A. 

      Product

    • B. 

      Amount

    • C. 

      Order

  • 20. 
    In a first-order reaction, the reaction rate is directly proportional to the concentration of _______ .
    • A. 

      Two or more reactants

    • B. 

      Both reactants and products

    • C. 

      Only one reactant

  • 21. 
    How do you determine the actual kinetic order of a reaction?
    • A. 

      The actual chemical order must be determined by experiment.

    • B. 

      The actual kinetic order must be determined by experiment.

    • C. 

      The actual potential order must be determined by experiment.

  • 22. 
    What is a reaction progress curve?
    • A. 

      A reaction progress curve is a graph of all the energy changes that occur as reactants are converted to products.

    • B. 

      A reaction progress curve is a graph of all the energy changes that occur as products are converted to reactants.

    • C. 

      A reaction progress curve is a graph of all the energy changes that occur as kentic energy is converted to products.

  • 23. 
    A(n) ______________________ reaction is one in which reactants are converted to products in a single step.
    • A. 

      Major

    • B. 

      Elementary

    • C. 

      Median

  • 24. 
    What is an intermediate product of a reaction?
    • A. 

      It is a product of a reaction that becomes a reactant of same reaction.

    • B. 

      It is a reaction of a product that becomes a reactant of another reaction.

    • C. 

      It is a product of a reaction that becomes a reactant of another reaction.

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