S&B enthalpy

What is heat energy?

A type of energy; heat represents the kinetic energy of the particles in a substance

What is temperature?

A measure of how much kinetic energy the particles have

A reaction that releases energy is

Exothermic

A reaction that releases energy does what?

Produces heat energy and increases temperature

A reaction that absorbs energy is

Endothermic

A reaction that absorbs energy does what?

Removes heat energy from the surroundings and decreases temperature

What is endothermic?

Heat energy is stored within substances as a different form of energy

What is exothermic?

Energy stored within substances is turned into heat energy

What is enthalpy (H)?

Chemical potential energy

What is enthalpy (H)?

A type of energy stored within a substance that can be released in the form of heat

What do enthalpy diagrams show?

Graphs that show how the amount of enthalpy in the reactants and products compare

What are the axes on an enthalpy diagram?

Y-axis = enthalpy; X-axis = reaction pathway/time

What is ΔrH?

The difference in enthalpy between products and reactants

What is ΔrH?

Enthalpy change for the reaction

How do you calculate ΔrH?

H(products) - H(reactants)

ΔrH value for an exothermic reaction

Negative (-)

ΔrH value for an endothermic reaction

Positive (+)