C7: Energy Changes Flashcards
Energy is _____ in chemical reactions. It is neither created or destroyed
Conserved
What is an exothermic reaction?
A reaction in which energy is transferred from the reacting substances to thier SURROUNDINGS
What is an endothermic reaction?
A reaction where energy is transferred to the reacting substancws from their surroundings
What can endothermic changes be used in?
Instant cold packs for sport injuries
What can exothermic changes be used in?
Hand warmers and self-heating cans
Bond making is ______
Exothermic
Bond breaking is_______
Endothermic
What is activation energy?
The minimum amount of energy needed before colliding particles have sufficient energy to causs a reaction
In chemical reactions, energy must be supplied to _________
Break the bonds between atoms in the reactants
When new bonds are formed between atoms in a chemical reaction what is released?
Energy
Describe an exothermic reaction
Energy released when new bonds are formed>energy absorbed when bonds are broken
Describe an endothermic reaction
Energy formed when new bonds are made
How can you calculate the overall energy change in a rection
Using bond energies
How are exothermic changes used?
Hand warmers and self heating cans
How are endothermic reactions used?
-instant cold packs for sports injuries
