Change in Enthalpy
What is the symbol for change in enthalpy?
Delta (triangle) H
Is lattice enthalpy exothermic or endothermic?
Endothermic
Is electron affinity exothermic or endothermic?
Exothermic.
Born Haber Cycles are a way to get what?
Lattice enthalpies
What is the symbol for change in entropy?
Delta S
What is the value for the change in enthalpy of an exothermic reaction?
Negative (<0)
What is the equation for the lattice enthalpy of NaCl?
NaCl(s) ---> Na+(g)+ Cl-(g)
What is the definition for electron affinity?
The enthalpy change when one mole of electrons are added to mole of gaseous atoms.
The compound in a Born Haber Cycle has to be a ____ and a ____.
Metal - Nonmetal (ionic)
Can an increase in entropy be described as more chaotic or orderly?
Chaotic
Is making bonds endothermic or exothermic?
Exothermic
How must molecules be bonded in order to have a lattice enthalpy?
Ionically
Would the electron affinity for a nonmetal be higher than that of a metal?
No, because nonmetals want another electron while metals do not.
The initial compound in a Born Haber Cycle has to be in a ____ state.
Solid
What is the definition of entropy?
The distribution of energy among the particles in a system.
What is name of a reaction where the products are less stable than the reactants?
Endothermic
What is the definition of lattice enthalpy?
The enthalpy change when one mole of a solid ionic compound is separated into gaseous ions under standard conditions.
What is the term for the opposite of electron affinity?
Ionization energy
What is atomization in a Born Haber Cycle?
The energy required to sublimate a solid cation.
Is the change in entropy of sublimation positive or negative?
Positive (solid to gas)
What is the definition of 'enthalpy'?
The total heat content of a system.
Why are lattice enthalpies endothermic?
The products are less stable than the reactants/bond are being broken so energy is released.
Yes, because it would become less stable.
What does FADIE stand for?
Formation, atomization, dissociation, ionization, and electron affinity
Are endothermic reactions experiencing more or less entropy and why?
More, because bonds are being broken, therefore increasing chaos and instability.