Chemical energetics

Exothermic reaction definition,releases heat to surroundings (temperature increases)

Endothermic reaction definition,absorbs heat from surroundings (temperature decreases)

Enthalpy change (ΔH) definition,heat energy change during a reaction

ΔH sign (exothermic),negative

ΔH sign (endothermic),positive

Activation energy definition,minimum energy needed for reaction to occur

Bond breaking,requires energy (endothermic)

Bond making,releases energy (exothermic)

Overall energy change,depends on bond breaking vs bond making

Bond energy calculation,ΔH = energy in − energy out

Exothermic explanation,more energy released than absorbed

Endothermic explanation,more energy absorbed than released

Reaction pathway diagram features,reactants products Ea ΔH

Catalyst effect,lowers activation energy

Effect of catalyst,speeds up reaction without being used up