Energy Changes Exo and Endo

Question 1

Define Heat of a reaction

Answer 1

The net change of chemical potential energy of the system

Question 2

Define Exothermic

Answer 2

reactions which transform chemical potential energy into thermal energy delta H is negative

Question 3

What are the characteristics of a an exothermic reaction

Answer 3

Exothermic reactions release heat and temperature of the reaction mixture will increase
release more energy than they absorb
form bonds, release more energy

Question 4

Define endothermic

Answer 4

Reactions which transforms thermal to chemical potential energy

Question 5

Define Activation energy

Answer 5

Minimum energy required to start a chemical reaction or the energy required to form the activated complex

Question 5

What are the characteristics of endothermic reaction

Answer 5

delta H is positive
absorb heat, the temperature of the reactions mixture will decrease
release less energy than they absor
Bond breaking is endothermic , require more energy

Question 6

Define Activated complex

Answer 6

High energy, unstable, temporary transition state between the reactants and the products