Reaction rates

Question 1

Define the activation energy:

Answer 1

The activation energy is the minimum energy required to start a chemical reaction.

Question 2

Define the activated complex:

Answer 2

The activated complex is a high energy, unstable, temporary transition state between the reactants and the products.

Question 3

Define a catalyst:

Answer 3

A catalyst is a substance that increases the rate of a chemical reaction, but remains unchanged at the end of the reaction.

Question 4

What is the reaction rate of a chemical reaction?

Answer 4

The reaction rate of a chemical reaction refers to the change in concentration per unit time of either a product or a reactant.

Question 5

What is meant by the heat of a reaction (ΔH)?

Answer 5

The heat of a reaction refers to the net change in the chemical potential energy of the system.

Question 6

Define an exothermic reaction:

Answer 6

An exothermic reaction is a reaction which transforms chemical potential energy into thermal energy.

Question 7

Define an endothermic reaction:

Answer 7

And endothermic reaction is a reaction which transforms thermal energy into chemical potential energy.