Question 1

Which of the following is true of a catalyst for a reaction?

Accepted Answer

A)   It decreases the equilibrium constant for the reaction.
B)   It increases the equilibrium constant for the reaction.
C)   It has no effect on the equilibrium constant for the reaction.
D)   Any of the above, depending on the reaction involved. C

Question 2

In a particular chemical reaction 4 bonds are broken and 3 bonds are formed. Based only on this information, which of the following is true?

Accepted Answer

A)   The reaction has a high activation energy.
B)   The reaction is endothermic.
C)   The reaction is exothermic.
D)   We cannot determine which of the above is true. D

Question 3

Which of the following units can used to describe the rate of a chemical reaction?

Accepted Answer

A)   (mol·L) /min
B)   (mol/L) /min
C)   1/(mol·L·min) 
D)   none of these B

Question 4

Then notation [A]4 is equivalent to which of the following?

Accepted Answer

A)   [A] + [A] + [A] + [A]
B)   1/([A] + [A] + [A] + [A]) 
C)   [A] × [A] × [A] × [A]
D)   1/([A] × [A] × [A] × [A])

Question 5

Which of the following is the equilibrium constant expression for the reaction?

Accepted Answer

A)   K = [CH3COOH][C2H5OH]/[CH3COOC2H5][H2O]
B)   K = [CH3COOC2H5][H2O]/[CH3COOH][C2H5OH]
C)   K = [CH3COOH][C2H5OH]/[CH3COOC2H5]
D)   K = [CH3COOC2H5]/[CH3COOH][C2H5OH]

Question 6

Silver iodide is an insoluble salt. If solid sodium iodide and solid silver nitrate are mixed together a reaction to for sodium nitrate and silver iodide occurs but it is extremely slow. However, if the sodium iodide and silver nitrate are first dissolved in water and the two solutions are mixed the reaction occurs very rapidly. Which of the following explain(s) the difference in reaction rates?

Accepted Answer

A)   Ions in solution have high mobility and ions of opposite charges are attracted to each other.
B)   The concentration of ions in solution is greater than the concentration of ions in the solid.
C)   both of the above
D)   neither of the above

Question 7

A catalyst speeds up a chemical reaction as a result of which of the following?

Accepted Answer

A)   It provides an alternate pathway with a lower activation energy.
B)   It increases the number of collisions between reacting molecules.
C)   It makes the reaction more endothermic.
D)   It makes the reaction more exothermic.

Question 8

For the reaction 2C → A + B, 0.01 mol of A is formed during the first 15 seconds of the reaction. Assuming that the rate of reaction remains constant for two minutes, which of the following statements is true?

Accepted Answer

A)   After 2 minutes 0.08 moles of B were produced.
B)   After 2 minutes 0.16 moles of C were consumed.
C)   both a and b
D)   neither a nor b

Question 9

For which of the following reactions is it important that the species collide with the correct orientation?

Accepted Answer

A)   2 H2(g)  + O2(g)  → 2 H2O(l) 
B)   HCl(g)  + H2O(l)  → H2O+(aq)  + Cl-(aq) 
C)   both of them
D)   neither of them

Question 10

In a certain chemical reaction 1.00 gram of product is produced in 15 minutes when the reaction is carried out at 20°C. Assuming that there is sufficient starting material available, about how much product will be produced in the same length of time if the reaction is carried out in a boiling water bath at 100°C?

Accepted Answer

A)   2.00 g
B)   16.0 g
C)   64.0 g
D)   256 g

Question 11

What is the effect of decreasing the temperature at which a reaction is carried out?

Accepted Answer

A)   In all cases the rate of reaction decreases.
B)   In virtually all cases the rate of reaction decreases.
C)   In all cases the rate of reaction increases.
D)   In virtually all cases the rate of reaction increases.

Question 12

Consider the following energy diagram for a reaction. 
-Which letter represents the net energy change of the reaction?

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   E

Question 13

Many molecular collisions do not result in chemical reaction. Why is this?

Accepted Answer

A)   The colliding molecules are not the correct chemicals.
B)   The colliding molecules do not have sufficient energy.
C)   The colliding molecules do not have the correct orientations.
D)   all of the above

Question 14

Which of the following is true of effective collisions?

Accepted Answer

A)   The number of effective collisions decreases as the temperature is increased.
B)   the number of effective collisions determines the reaction rate.
C)   both a and b
D)   neither a nor b

Question 15

For the reaction  at 472°C equilibrium is established when [H2] =0.0200M, [N2] = 0.0100M and [NH3] = 5.37 × 10-8M. What is the equilibrium constant for this reaction?

Accepted Answer

A)   2.69 × 10-4
B)   3.60 × 10-8
C)   7.21 × 10-10
D)   7.21 × 10-11

Question 16

For which of the following reactions is it important that the species collide with the correct orientation?

Accepted Answer

A)   HCl(g)  + H2O(l)  → H2O+(aq)  + Cl-(aq) 
B)   Ag+(aq)  + Cl-(aq)  → AgCl(s) 
C)   both of them
D)   neither of them

Question 17

Which of the following statements is true about a reversible reaction?

Accepted Answer

A)   All reversible reactions are exothermic.
B)   All reversible reactions have low activation energy.
C)   When we mix the reactants together one or more of the reactants will be completely used up.
D)   When we mix the reactants together none of the reactants will be completely used up.

Question 18

In an energy diagram for an endothermic chemical reaction which of the following is true?

Accepted Answer

A)   The energy of the products is lower than that of the reactants.
B)   The energy of the transition state is higher than that of the reactants.
C)   both a and b
D)   neither a nor b

Question 19

Consider the following energy diagram for a reaction. 
-Which letter represents the transition state?

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   E

Question 20

Consider the following energy diagram for a reaction. 
-In the reaction of HCl with water: HCl(g) + H2O(l)  H 3O+(aq) + Cl- (aq)
The following species forms.  Which letter represents this species?

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   E

Exam 7: Reaction Rates and Chemical Equilibrium

Which of the following is true of a catalyst for a reaction?

In a particular chemical reaction 4 bonds are broken and 3 bonds are formed. Based only on this information, which of the following is true?

Which of the following units can used to describe the rate of a chemical reaction?

Then notation [A]⁴ is equivalent to which of the following?

Which of the following is the equilibrium constant expression for the reaction?

A catalyst speeds up a chemical reaction as a result of which of the following?

For the reaction 2C → A + B, 0.01 mol of A is formed during the first 15 seconds of the reaction. Assuming that the rate of reaction remains constant for two minutes, which of the following statements is true?

For which of the following reactions is it important that the species collide with the correct orientation?

What is the effect of decreasing the temperature at which a reaction is carried out?

Consider the following energy diagram for a reaction. -Which letter represents the net energy change of the reaction?

Many molecular collisions do not result in chemical reaction. Why is this?

Which of the following is true of effective collisions?

For the reaction at 472°C equilibrium is established when [H₂] =0.0200M, [N₂] = 0.0100M and [NH₃] = 5.37 × 10^-8M. What is the equilibrium constant for this reaction?

For which of the following reactions is it important that the species collide with the correct orientation?

Which of the following statements is true about a reversible reaction?

In an energy diagram for an endothermic chemical reaction which of the following is true?

Consider the following energy diagram for a reaction. -Which letter represents the transition state?

Consider the following energy diagram for a reaction. -In the reaction of HCl with water: HCl(g) + H₂O(l) H ₃O⁺(aq) + Cl^- (aq) The following species forms. Which letter represents this species?

Exam 7: Reaction Rates and Chemical Equilibrium

Which of the following is true of a catalyst for a reaction?

In a particular chemical reaction 4 bonds are broken and 3 bonds are formed. Based only on this information, which of the following is true?

Which of the following units can used to describe the rate of a chemical reaction?

Then notation [A]4 is equivalent to which of the following?

Which of the following is the equilibrium constant expression for the reaction?

A catalyst speeds up a chemical reaction as a result of which of the following?

For the reaction 2C → A + B, 0.01 mol of A is formed during the first 15 seconds of the reaction. Assuming that the rate of reaction remains constant for two minutes, which of the following statements is true?

For which of the following reactions is it important that the species collide with the correct orientation?

What is the effect of decreasing the temperature at which a reaction is carried out?

Consider the following energy diagram for a reaction. -Which letter represents the net energy change of the reaction?

Many molecular collisions do not result in chemical reaction. Why is this?

Which of the following is true of effective collisions?

For the reaction at 472°C equilibrium is established when [H2] =0.0200M, [N2] = 0.0100M and [NH3] = 5.37 × 10-8M. What is the equilibrium constant for this reaction?

For which of the following reactions is it important that the species collide with the correct orientation?

Which of the following statements is true about a reversible reaction?

In an energy diagram for an endothermic chemical reaction which of the following is true?

Consider the following energy diagram for a reaction. -Which letter represents the transition state?

Consider the following energy diagram for a reaction. -In the reaction of HCl with water: HCl(g) + H2O(l) H 3O+(aq) + Cl- (aq) The following species forms. Which letter represents this species?

Then notation [A]⁴ is equivalent to which of the following?

For the reaction at 472°C equilibrium is established when [H₂] =0.0200M, [N₂] = 0.0100M and [NH₃] = 5.37 × 10^-8M. What is the equilibrium constant for this reaction?

Consider the following energy diagram for a reaction. -In the reaction of HCl with water: HCl(g) + H₂O(l) H ₃O⁺(aq) + Cl^- (aq) The following species forms. Which letter represents this species?