Enthalpy

youtube.com/watch?v=s09cfeirxgA&feature=youtu.be

What is enthalpy

Refers to all the heat energy that is stored in a chemical system (all of the chemicals present in the reaction)

Enthalpy is said when referring to energy in reactions.

How can we calculate enthalpy change

Enthalpy change = (H) Products - (H) reactants

Triangle represents change in. H = enthalpy

When is delta (triangle) H negative.

When enthalpy of products is less than reactants, this is shown with downward pointing arrow

This tells us heat energy was released from chemical system to surroundings (exothermic)

Ea is activation energy, it points up

Whats activation energy

Minimum energy required for reaction to take place.

What is shown in endothermic reaction on enthalpy profile

Enthalpy of products is greater than enthalpy of reactants , this means delta H is positive, and the arrowhead points upwards

This tells us the chemical system has taken in heat energy from the surroundings, this is endothermic.

The temp of surroundings will decrease.

Activation energy arrow points upwards always. Runs from enthalpy of reactants to peak of curve