02. Conservation of energy

What does the principle of conservation energy state?

Energy cannot be created or destroyed, only converted from one form to another

What are the energy changes in chemical reactions usually?

Usually in the form of heat and can be exothermic or endothermic

What are 4 characteristics of an exothermic reaction?

1) Heat released 2) triangle H is negative 3) Products have less energy than reactants 4) Energy gain by surroundings is identified by temperature rise

Draw exothermic reaction on a graph

yes

What are 4 characteristics for an endothermic reaction?

1) Heat absorbed 2) triangle H is positive 3) products have more energy than reactants 4) Energy loss by surroundings is identified by drop in temperature

Draw an endothermic graph

Yes

What is activation energy

Minimum energy which reacting species must have before a reaction can occur