Chapter 5

Question 1

Combination Reaction

Answer 1

Two molecules come together to form an intermediate that decomposes to produce two final products

Question 2

Rate-determining Step

Answer 2

Slowest step of a reaction
* Determines overall rate of reaction
* Reaction can only proceed as fast as rate-determining step

Question 3

Activation Energy

Answer 3

Minimum energy needed for a chemical reaction to occur
* Distance on y-axis from energy of reactants to peak energy before formation of products
* Lowest activation energy = fastest rate of reaction

Question 4

Transition State Theory

Answer 4

Focuses on forming high-energy activated complex that can then proceed forward/backward, forming products or reverting to reactants

• Requires certain activation energy to be overcome for a reaction to occur

Question 5

Collision Theory

Answer 5

Focuses on energy and orientation of reactants and considers each potential reaction to be all-or-nothing (either enough energy to form products or not)

• Requires certain activation energy to be overcome for a reaction to occur

Question 6

Zero-Order Reaction

Answer 6

Have constant rate that doesn’t depend on concentation of reactant

• Temperature lowered: rate decreased
• All reactants’ concentrations doubled: rate unaffected
• Catlyst added: rate increased

Question 7

First-Order Reaction

Answer 7

Has a nonconstant rate that depends on concentration of reactant
* Temperature lowered: rate decreased
* All reactants’ concentrations doubled: rate doubled
* Catalyst added: rate increased

Question 8

Second-Order Reaction

Answer 8

Has nonconstant rate that depends on concentration of reactant
* Temperature lowered: rate decreased
* All reactants’ concentrations doubled: rate multiplied by 4
* Catalyst added: rate increased

Question 9

Endothermic

Answer 9

Question 10

Exothermic

Answer 10

Question 11

Spontaneous Reaction (Exergonic)

Answer 11

Net free energy change is negative

Question 12

Nonspotaneous (Endergonic) Reaction

Answer 12

Net free energy change is positive

Question 13

Rate of Reaction

Answer 13

• Temperature directly affects rate constant
• Changing partial pressure of gas will affect number of effective collisions per time
• Solvents affect rate of reactions depending on reaction solvent interaction

Question 14

Saturated Catalyst

Answer 14

• Have maximum turnover rate
• Can’t increase rate constant or reaction rate any higher by adding more reactant

Question 15

Catalyst

Answer 15

Increases the rate of reaction by lowering the activation energy making it easier for both forward and reverse reactions to overcome energy barrier
* Not used up
* Don’t alter equilibrium of reaction
* Stabilize transition state by lowering energy, not raising or eliminating