A3 - Enthalpy Changes Flashcards
Define enthalpy change
Heat energy change at constant pressure
What is the symbol for enthalpy change?
ΔH
What does ΔH mean?
Enthalpy change
What are the units for enthalpy change?
kJ mol−1
What happens in an exothermic process?
Energy is released from reactants to surroundings.
What happens in an endothermic process?
Energy is taken in from the surroundings to reactants.
In what type of process is energy is taken in from the surroundings to reactants?
Endothermic
In what type of process is energy released from reactants to surroundings?
Exothermic
What happens to the temperature of the surroundings in an exothermic process?
Temperature of surroundings increases
What happens to the temperature of the surroundings in an endothermic process?
Temperature of surroundings decreases
In what type of process does the temperature of surroundings increase?
Exothermic
In what type of process does the temperature of surroundings decrease?
Endothermic
What sign does the enthalpy change have for an exothermic process?
Exothermic processes have negative enthalpy changes
What sign does the enthalpy change have for an endothermic process?
Exothermic processes have positive enthalpy changes
What type of process has a negative enthalpy change?
Exothermic
