Unit 12 Practice Test

Flashcards based on Unit 12 Practice Test lecture notes.

What is another name for the activated complex?

Transition state.

What is activation energy?

An energy barrier between reactants and products.

How does a catalyst work?

By lowering the activation energy barrier.

In a reversible reaction, what are the relative amounts of reactant and product at the end of the reaction?

Some product and some reactant.

What happens to a reaction at equilibrium when more reactant is added to the system?

The reaction makes more products.

In a reaction at equilibrium that makes more moles of gas than it consumes, what is the effect of increasing the pressure?

The reaction makes more reactants.

In an equilibrium reaction with a Keq of 1 x 10^8, what is favored?

The products are favored.

What is the energy available to do work in a reaction called?

Free energy.

Which physical state of nitrogen has the highest entropy?

Gas.

What measures the amount of disorder in a system?

Entropy.

Which reaction results in the greatest increase in entropy?

A -> 2B

What explains why the melting of ice is a spontaneous reaction at room temperature and pressure?

Melting is accompanied by an increase of entropy.

What two factors determine whether a reaction is spontaneous or nonspontaneous?

Enthalpy change and entropy change.

What is one characteristic of spontaneous reactions?

Always releases free energy

What determines whether or not a reaction is spontaneous?

Enthalpy change and entropy change

Which of the following would increase the rate of the following reaction? S8(s) + 8O2(g) -> 8SO2(g)

increase the surface area of the oxygen

When nitrous oxide is converted to nitrogen and oxygen, what is the term used to describe the oxygen atoms formed?

products

What is an elementary reaction?

converts reactants to products in a single step

Which of the following would decrease the rate of the following reaction? S8(s) + 8O2(g) -> 8SO2(g)

increase the volume of the reaction container

What information is NOT given by an overall equation for a chemical reaction?

the probable order of the reaction