Thermochemistry Flashcards
Energy
Capacity for doing work/releasing heat
Thermochemistry
Study of energy changes that occur during phase changes or chemical reactions
Chemical Potential Energy
Energy stored in chemical bonds
Heat
Flows from warm to cool until the objects are at an equal heat, represented by a q
Exothermic Reaction
System loses heat and the surroundings heat up, q would be negative
Endothermic Reaction
System gains heat and the surroundings cool, q would be positive
calorie (cal)
Amount of heat needed to raise 1 gram of water by 1 degree Celsius, 1 calorie = 4.184 J
Heat Capacity
Amount of heat needed to raise an objects temperature by 1 degree Celsius, depends on mass and chemical composition
Specific Heat
Represented by a c, amount of heat needed to raise a specific substance’s heat by 1 degree Celsius
Enthalpy
Represented by H, the heat content of a system at constant pressure
Enthalpy Change
Represented by ΔH, the heat that enters or leaves a system at constant pressure
What does a negative ΔH mean?
An exothermic reaction has occured
What does a positive ΔH mean?
An endothermic process has occurred
What does it mean when ΔH is in the reactants of a chemical equation?
An endothermic reaction has occurred
What does it mean when ΔH is in the products of a chemical equation?
An exothermic reaction has occurred
