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

24 Questions | By Verdun | Updated: Mar 21, 2022 | Attempts: 68

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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.