Question :
21. Identify the catalyst in the following three-step process for : 1335519
21. Identify the catalyst in the following three-step process for the decomposition of ozone.
O3(g) O2(g) + O(g)
NO(g) + O3(g) ? NO2(g) + O2(g)
O(g) + NO2(g) ? O2(g) + NO(g)
A) O(g) B) O3(g) C) O2(g) D) NO(g) E) NO2(g)
22. Identify the catalyst in the following three-step reaction.
NO(g) + O2(g) ? NO3(g)
NO3(g) + NO(g) ? 2NO2(g)
NO2(g) + SO2(g) ? NO(g) + SO3(g)
A) SO2(g) B) NO3(g) C) O2(g) D) NO(g) E) NO2(g)
A)stable molecules that are formed during an early step of a reaction, and consumed in a later step.
B)materials which act to increase the rate of a reaction without themselves being consumed.
C)substances which form during a reaction that have a definite, well-known structure.
D)short-lived, high-energy chemical species that are produced during a reaction.
E)a molecular species with normal chemical bonds that is produced during a reaction.
24. When a chemical system has reached equilibrium:
A)the forward and reverse reactions have stopped.
B)the rate of the forward reaction is greater than the rate of the reverse reaction.
C)the rate of the forward reaction is less than the rate of the reverse reaction.
D)the rate of the forward reaction is equal to the rate of the reverse reaction.
E)the equilibrium constant has reached a minimum.
25. In order to write the equilibrium constant expression for a reaction, you must:
A)know the mechanism for the reaction.
B)know the rate of the forward and reverse reactions.
C)know the concentrations of all reactants and products.
D)have the balanced chemical equation for the reaction.
E)know the conditions of pressure, temperature, and concentration for the system.
26. The graph shows the change in concentration of reactant and product as a reaction proceeds. At what point is equilibrium first reached?
A) I B) II C) III D) IV E) V
27. If the following reaction is carried out in a sealed container:
2SO3(g) 2SO2(g) + O2(g)
a state of equilibrium can be reached if the container initially contains:
A)SO3 only.
B)SO2 and O2 only.
C)SO3 and O2 only.
D)SO3, SO2, and O2.
E)any of these combinations of reactants and products.
28. If the following reaction is carried out in a sealed container:
N2(g) + 3H2(g) 2NH3(g)
a state of equilibrium can be reached if the container initially contains:
A)NH3 only.
B)N2 and H2 only.
C)NH3 and N2 only.
D)NH3, N2, and H2.
E)any of these combinations of reactants and product.
29. A chemical reaction can reach a state of equilibrium
A)only from the reactants side.
B)only from the products side.
C)only when both products and reactants are present initially.
D)by starting from either the reactant or the product side.
E)from all reactants and at least one product.
30. Consider the sublimation of solid iodine in a closed container:
I2(s) I2(g)
What kind of measurements could you make to determine if this physical change has reached a state of equilibrium?
A)measure changes in the volume of the container
B)measure changes in the mass of the contents of the container
C)measure changes in pressure inside the container
D)measure changes in temperature inside the container
