Chapter 18 Reaction Rates And Equilibrium
In layman’s terms, equilibrium is defined as a state of balance due to equal reactions of opposing forces, and today we’ll be talking all about it with regards to the scientific study of chemistry, focusing on such topics as reaction rates. What can you tell us? Let’s find out.
- 1.How are rates of chemical change expressed?
- A.
Rates of chemical change are usually expressed as the amount of energy changing per unit time.
- B.
Rates of chemical change are usually expressed as the amount of non- reactant changing per unit time.
- C.
Rates of chemical change are usually expressed as the amount of reactant changing per unit time.
- 2.Look at Figure 18.3 on page 542. In a typical reaction, as time passes, the amount of____________ decreases and the amount of ____________ increases.
- A.
Reactant, product
- B.
Cataltyst, energy
- C.
Inhibitor, equilibrium
- 3.What does collision theory say about atoms, ions, ormolecules reacting to form products when they collide?
- A.
Collision theory states that the particles must have enough kinetic energy when they collide to form products.
- B.
Collision theory states that the particles must have enough potential energy when they collide to form products.
- C.
Collision theory states that the particles must have enough no kinetic energy when they collide to form products.
- 4.Particles lacking the necessary kinetic energy to react bounce apart ____________ when they collide.
- A.
Reactant
- B.
Changed
- C.
Unchanged
- 5.Look at Figure 18.5 on page 543. Which arrangement of atoms contains the least amount of energy?
- A.
Reactants
- B.
Activated complex
- C.
Products
- 6.Circle the letter of the term that completes the sentence correctly. The minimum amount of energy that particles must have in order to react is called the _______ .
- A.
Kinetic energy
- B.
Activation energy
- C.
Potential energy
- D.
Collision energy
- 7.An activated complex is the arrangement of atoms at the ______________________ of the activation-energy barrier.
- A.
Product
- B.
Reactant
- C.
Peak
- 8.Circle the letter of the term that best describes the lifetime of an activated complex.
- A.
10–15 s
- B.
10 13 s
- C.
10–13 s
- D.
10–1 s
- 9.Why is an activated complex sometimes called the transition state?
- A.
It is called the transition state because an activated complex is unstable and is as likely to re-form reactants as it is to form products.
- B.
It is called the transition state because an activated complex is stable and is as likely to re-form reactants as it is to form products.
- C.
It is called the transition state because an activated complex is unstable and is as likely to re-form reactants as it is to form reactant.
- 10.Changes in the rate of chemical reactions depend on conditions such as
- A.
Reactant, product, and activation
- B.
Temperature, concentration, and particle size
- C.
Collision, intervals, and kenetic energy
- 11.The main effect of increasing the temperature of a chemical reaction is to ______________________ the number of particles that have enough kinetic energy to react when they collide.
- A.
Increase
- B.
Decrease
- C.
Interpret
- 12.What happens when you put more reacting particles into a fixed volume?
- A.
The concentration of reactants increases, the collision frequency increases, and, therefore, the reaction rate decreases.
- B.
The concentration of reactants increases, the collision frequency increases, and, therefore, the reaction rate increases.
- C.
The concentration of reactants decreases, the collision frequency increases, and, therefore, the reaction rate increases.
- 13.The smaller the particle size, the larger the surface area of a given _____________.
- A.
Absorbant of a particle.
- B.
Mass of a particle.
- C.
Release of a particle.
- 14.What are some ways to increase the surface area of solid reactants?
- A.
One way is to dissolve the solid; another way is to grind the solid into a fine powder.
- B.
One way is to leave it as a solid; another way is to make it into a liquid.
- C.
One way is to make into a vapor; another way is to change it into rough powder.
- 15.A ______________________ is a substance that increases the rate of a reaction without being used up itself during the reaction.
- A.
Product
- B.
Reactant
- C.
Catalyst
- 16.What does a catalyst do?
- A.
A catalyst permits reactions to proceed at a lower energy than is normally required. A catalyst lowers the activation energy.
- B.
A catalyst permits reactions to proceed at a higher energy than is normally required. A catalyst lowers the activation energy.
- C.
A catalyst permits reactions to proceed at a lower energy than is normally required. A catalyst raises the activation energy.
- 17.In a chemical equation, how do you show that catalysts are not consumed or chemically altered during a reaction?
- A.
The catalyst is often written above the stop arrow in the equation.
- B.
The catalyst is often written below the yield arrow in the equation.
- C.
The catalyst is often written above the yield arrow in the equation.
- 18.A(n) ______________________ is a substance that interferes with the action of a catalyst.
- A.
Particle size
- B.
Reactant
- C.
Inhibitor
- 19.What happens in reversible reactions?
- A.
In reversible reactions, two opposite products occur simultaneously.
- B.
In reversible reactions, two opposite reactions occur simultaneously.
- C.
In reversible reactions, two of the same reactions occur simultaneously.
- 20.Chemical equilibrium is a stateof balance in which the rates of forward and reverse reactions __________; no net change in the amount of reactants and products occurs in the chemical system.
- A.
Not equal
- B.
Are equal
- C.
The same at some points
- 21.The equilibrium position of a reaction is given by the relative_______________ of the system’s components at equilibrium.
- A.
Pressure
- B.
Concentration
- C.
Temperature
- 22.At equilibrium, how many types of molecules are present in
- A.
3
- B.
6
- C.
9
- 23.What is Le Châtelier’s principle?
- A.
Le Châtelier’s principle states that if a stress is applied to a system in dynamic no equilibrium, the system changes to relieve the stress.
- B.
Le Châtelier’s principle states that if a stress is applied to a system in dynamic equilibrium, the system changes to relieve the stress.
- C.
Le Châtelier’s principle states that if a stress is applied to a system in dynamic equilibrium, the system stays the same to relieve the stress.
- 24.Stresses that upset the equilibrium of a chemical system include changes in _______
- A.
Kentic, potinial, and reactants
- B.
Reactant, products, and balance
- C.
Concentration, pressure, and temperature.
- 25.When you add a product to a reversible chemical reaction, the reaction is always pushed in the direction of ______________________ .
- A.
Products
- B.
Reactants
- C.
Equilbrium
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