12B.1 Flashcards
what is standard lattice energy
the energy change is measured at standard conditions when one mole of an ionic compound is formed from its ions in a gaseous state
what is an example of Hle
Na^+(g) + Cl^-(g) ——> NaCl(s) KJ/mol
what are the factors that affect lattice energy
- the charge of the cation (the larger the stronger)
- the number of cation-anion interactions ( the more the stronger)
- the distance between the cation and anion (their ionic radii), this distance depends on their size, the smaller the larger the energy
- the type of lattice
what is standard entahlpy of atomazation
the energy change is measured at standard conditions when one mole of an atom in a gaseous state is formed from its elements in their standard state
what is electron affinity
the energy change when one atom in a mole of atoms in a gaseous state gains one electron to form a negative 1- ion
example of an electron affinity equation
Li(g) +b e^- —–> Li^-
what is the exception for noble gases for the first EA (electron affinity)
a noble gas as a full outter shell so when the electron is added it goes to a new shell making the EA positive when it is usually always negative
why is the second EA positive
because energy is required to overcome the repulsion between the negative ion and the electron being added
How do you find out if making a negative ion of O (O^-2) or anything similar is an Endo or Exo process
by finding the first EA and the second EA and then adding them if the overall EA is positive then its Endo if the overall EA id negative then it Exo
is a noble gas structure required for stable compound
no its not
why do we form Ca^2+O^-2 rather than Ca^+O^-
because Ca^2+O^-2 has a much larger lattice energy os its more energetically stable
what can affect the overall energy change in a reaction
the conditions it is carried under
