C7 - Energy Changes Flashcards
Hat is an exothermic reaction?
A reaction which transfers energy to the surroundings.
What happens to the the temperature in an exothermic reaction?
It rises
What are some examples of exothermic reactions?
Combustion
Neutralisation reactions (acid + alkali)
Oxidation reactions
What is an endothermic reaction?
A reaction that takes in energy from the surroundings
What happens to the temperature in a endothermic reaction?
It falls
What is are some examples of an endothermic reaction?
Thermal decomposition
Electrolysis
What are reaction profiles?
Diagrams that show the relative energies of the reactants and products, and how energy changes throughout the reaction
How would you know if a reaction profile is exothermic?
The products are at a lower energy than the reactants.
What reprsents the activation energy on reaction profile diagrams?
The intial rise of energy needed to start the reaction
What is activation energy in depth?
The minimum amount of energy needed for the reactants to collide with each other and react
The greater the activation energy, the more _____________________________________
Energy needed to start the reaction
How would you know if a reaction profile is endothermic?
The products are at a HIGHER energy than the reactants.
What happens to bonds during chemical reactions?
Old bonds are broken and new bonds are formed
Energy must be ________ to break existing bonds
Supplied
Energy is ________ when new bonds are formed
Released
