Chapter 17 Take-Home Exam

1. One factor that cannot be adjusted in order to improve a reaction rate is

• temperature.

• surface area.

• nature of the reactant.

• concentration.

An activated complex can best be described as a(n)

• unstable arrangement of colliding particles that can rearrange to form products.

• high-energy complex that is stable enough to isolate and characterize.

• high-energy molecule with strong bonds and a stable structure.

• stable molecule with a long lifetime.

Catalysts affect reaction rates by

• forming an activated complex with lower energy.

• broadening the energy barrier.

• increasing the activation energy.

• changing the net thermodynamics of the reaction.

A rate law relates

• reaction rate and temperature.

• reaction rate and concentrations of reactants.

• temperature and concentrations of reactants.

• energy and concentrations of reactants.

What impact does an increase in temperature generally have on the rate of a reaction?

• It increases it.

• It has no impact.

• There is no way to measure the change.

• It decreases it.

If the concentration of a reactant in a mixture is tripled and the reaction rate increases by

a factor of nine, the reaction order with respect to that reactant is

• zero.

• one.

• two.

• three.

The minimum energy that two colliding molecules need before a chemical transformation

can take place is the

• rate-determining energy.

• activation energy.

• reaction order energy.

• activated complex energy.

A temporary union of atoms that forms after reactants have begun reacting but before

products have formed is known as a(n)

• catalyst.

• enzyme.

• activated complex.

• mechanism.

The rate-determining step of a reaction is always the

• first step.

• last step.

• fastest step.

• slowest step.

The value of ΔE for an endothermic reaction is always

• positive.

• negative.

• zero.

• unknown.