Energetics Flashcards
What are the standard conditions for enthalpy change?
-100kPa
-298K
What is an exothermic reaction?
-Give out energy to surroundings
-Products end up with less energy than reactants
-Enthalpy change is negative
What is an endothermic reaction?
-Takes in energy from surroundings
-Products end up with more energy than reactants
-Enthalpy change is positive
What is bond enthalpy?
-The energy needed to break a bond
Is bond breaking endothermic or exothermic?
-Endothermic
What is standard enthalpy change of formation?
-The enthalpy change when 1 mole of a compound is formed from its elements in their standard states, under standard conditions
What is the standard enthalpy change of combustion?
-The enthalpy change when 1 mole of a substance is completely burned in oxygen under standard conditions, with all reactants and products in their standard states
What is the standard enthalpy change of reaction?
-The enthalpy change when a reaction occurs in the molar quantities shown in the chemical equation, under standard conditions with all reactants and products in their standard states
What is the equation to calculate enthalpy change?
q=mc_T
q=heat lost of gained (J)
m=mass (g)
c=specific heat capacity
_T=temperature change
What is Hess’s law?
-The total enthalpy change for a reaction is independent of the route taken
