Enthaply and Entropy Flashcards
what does the lattice enthaply mean?
the enthalpy change that accompanies the formatuions of one mole of an ionic compound from its gaseous ions under standard conditions
latice enthaply down a group
ionic rradius increases
attraction between ions decreases
lattice energy less negative
melting point decreases
lattice enthaply across a period
ionic charge increases
attraction between opns increases
lattice enthaply more neagive
melting point increases
can we measure lattice enthaply directly?
No, we use an enthaply diagram to work it out
what is the standard enthaply change of atomisation?
the enthaply change when a mole of gaseous atoms is formed from elemetns in their standard states (298k, 1` atm)
what is the 1st ionisation energy
the amount of energy required to remove one electron from every atom in one mole of gaseous atoms to form a mole of gaseous 1+ ions
what is the 2nd ionisation energy?
the amount of energy required to remove one electron from every ion in one mole of gaseous 1+ ions to form a mole of gaseous 2+ ions
what is the standard enthaply change of formation?
the enthaply chagne when a mole of a compound is formed from its elements in thier standard states, under standard condition (1atm, 298k)
what is first electron affinity
the enthalpy change that takes place when one electrons is added to each atom is one mole of gaseous atoms to form one mole of gaseous 1- ions.
what is the second electron affintiy?
the enthalpy change that takes place when one electrons is added to each ion is one mole of gaseous 1- ions to form one mole of gaseous 2- ions.
what to remember when there is a second electron affinity?
the second electron affintiy must contain an electron
waht does lattice enthaply equal to?
enthaply change of formation - everythign elese
what is the standard enthaply change of solution?
the enthaply change when a mole of an ionic solid compound is completely dissolved in water under standard conditions (298k, 1 atm)
what type of reaction is more soluble?
exothermic means more soluble
what is the standard enthaply change of hydration?
The exotrhermic enthaplky change when a mole of isolated gaseous ions is dissolved in water to from a mole of aquesous ions under standard condition (298k, 1 atm)
what does a born haber cycle with solution and hydration look like?
what is entropy?
a measure of the dispersal of ernergy in a system which is greater, the more disordered a system
States from least to most entropy
solid
liquid
solutions
gases
what has a higher entropy, 2 or 4 moles of gas?
4 moles of gas
how to calculate the entropy?
entropy of products - entropy of reactatns
how to calculate entropy?
entropy of products - entropy of reactatns
what is the gibbs free energy equation
when is a reaction spontaneous/feasable?
when ΔGis -ve
what does a normal born hber cycle look like?
