9. Enthalpy Flashcards
What is enthalpy?
A measure of heat energy in a chemical system.
What is enthalpy change?
Difference in enthalpy between reactants and products in a reaction.
What symbol is used to represent enthalpy change?
ΔH
What is the law of conservation of energy?
Energy cannot be created or destroyed
What is an exothermic reaction?
A reaction in which the enthalpy of products is smaller than the enthalpy of reactants results in heat energy being released to the surroundings.
Will ΔH be positive or negative in an exothermic reaction?
Negative
Will the chemical system gain or lose energy in an exothermic reaction?
Lose
Will the surroundings gain or lose energy in an exothermic reaction?
Gain
Will the temperature of surroundings increase or decrease in an exothermic reaction?
Increase
What is an endothermic reaction?
A reaction in which the enthalpy of products is greater than the enthalpy of reactants, resulting in heat energy being taken in from the surroundings.
Will ΔH be positive or negative in an endothermic reaction?
Positive
Will the chemical system gain or lose energy in an endothermic reaction?
Gain
Will the surroundings gain or lose energy in an endothermic reaction?
Lose
Will the temperature of surroundings increase or decrease in an endothermic reaction?
Decrease
