issues Eco-cars
diets
Specific heat
Enthalpy
enthalpy
H
• = heat change at constant
pressure
+
-
Hess’s Law
• =H or Hrxn Q H vs. q? H = q when pressure is constant • Endothermic • Exothermic Reactions Reactions H is positive H is negative
Free energy
sources
units
Water, ice, and steam
types
Energy
Energy: What Changes Should We Make?
issues
diets
Specific heat
enthalpy
5. Standard Enthalpies of Vaporization and Fusion. For water:
• H2O(l)H2O(g) Hovap = 2260J/g
gas 2260 J/g
• H2O(s)H2O(l) Hofus = 334 J/g
Hcond
Hvap
-2260 J/g
334 J/g
Hfus
Hsolid -2260 J/g solid
Hess’s Law
sources
liquid
Free energy
Eco-cars
units
Water, ice, and steam
types
Energy
Energy: What Changes Should We Make?
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