AP Chemistry 5.4-5.10

Front

What is activation energy (E_a)?

Back

The minimum energy required for a chemical reaction to occur.

Front

What characterizes an endothermic reaction?

Back

An endothermic reaction absorbs heat from its surroundings.

Front

What characterizes an exothermic reaction?

Back

An exothermic reaction releases heat to its surroundings.

Front

What is a reaction intermediate?

Back

A species that is formed in one elementary step and consumed in a subsequent step of a reaction mechanism.

Front

How do you determine the number of elementary steps in a reaction mechanism?

Back

Count the individual steps that make up the overall reaction.

Front

What is the difference between a catalyst and an intermediate?

Back

A catalyst speeds up a reaction without being consumed, while an intermediate is formed and consumed during the reaction.

Front

What is the significance of the rate-determining step in a reaction mechanism?

Back

It is the slowest step that determines the overall rate of the reaction.

Front

How does temperature affect reaction rates?

Back

Increasing temperature generally increases reaction rates by providing more energy to the reactants.

Front

What is the Arrhenius equation?

Back

k = A * e^(-E_a/RT), where k is the rate constant, A is the frequency factor, E_a is the activation energy, R is the gas constant, and T is the temperature in Kelvin.

Front

What is the role of a catalyst in a chemical reaction?

Back

A catalyst lowers the activation energy, increasing the rate of the reaction without being consumed.