General Chemistry 2: Enthalpy(STEM).pptx

GenChem 2

1. GENCHEM2

2. GENCHEM2 ENTHALPY the heat content of a system heat that passes into or out of the system during a reaction is the enthalpy change

3. ENTHALPY the heat content of a system change of a reaction is roughly equivalent to the amount of energy lost or gained during the reaction A reaction is favored if the enthalpy of the system decreases over the reaction

4. We can think of change in enthalpy as the change in energy. Or the energy stored in all the bonds of the products minus the energy stored in the all the bonds of the reactants.

5. product - reactant Δ H = positive: endothermic reaction product - reactant Δ H = negative: exothermic reaction

6. HEAT

7. HEAT (q) energy that flows between a system and its surroundings due to a difference in temperature higher temperature to lower temperature “Hi – Lo”

8. HEAT (q) q is negative if the heat is being released by the system q is positive if it is absorbed by the system

9. HEAT (q) q = Δ H at constant T and P J (joules) = kJ 1 calorie = 4.184 J

10. HEAT (q) q = Δ H at constant T and P

11. ENTHALPY ACTIVITY