ap chemistry frq power words

Coulombic Attraction

Coulombic Attraction

use anywhere that a concept requires the consideration of an interaction between charged species. especially useful when discussing periodic trends such as ionization energies. use instead of “shielding”.

particle

this word covers the more specific terms like atoms, molecules, and ions, and is deliberately ambiguous.

dipoles cancel through/via symmetry

used when explaining that polar bonds within a Lewis structure lead to a non-polar molecule due to the dipoles cancelling out by pointing towards each other.

greater polarizability

use to describe the increase in LDFs that occurs with the increasing number of electrons and increasing surface area of molecules. do not use “increasing mass” in conjunction with increasing LDFs, since mass changes relating to attractive forces are only applicable to gravitational forces, not any forces occurring between particles.

protonated, deprotonated

describes acids and their conjugate bases

successful collision

a collision that results in a reaction. one that fulfills both the activation energy and the orientation criteria.

unsuccessful collision

collisions that do not result in a reaction, due to too low activation energy or improper orientation

catalysts are regenerated

in reactions where catalysts undergo chemical interactions with reactants, they actually do take part in the reaction. That is why when they show up in both the products and reactions, they are “regenerated,” not “not used in the reaction.”

kJ/mol rxn

refers to the enthalpy change “for the reaction as written,” meaning that the numerical value you see for delta H is what applies to the reaction as a whole.

restore the value of K

useful when explaining a shift in equilibrium position at constant temperature that occurs because of an external stress and the subsequent creation of a Q value that must be counteracted.

buffers resist change in pH

pHs do change when acids and bases are added to buffers, but not as much as one might expect because they are capable of accepted both H+ and OH-.

dispersal

replaces “disorder” in terms of entropy, more emphasis when you say dispersal

kinetically stable

used to describe reactions with high activation energies making otherwise thermodynamically favorable reactions (negative ∆G°) appear not to proceed

kinetic control

the barrier that prevents reactions from occurring, due to the activation energy being too high to proceed at a rate that can be recorded.

thermodynamically favored

when a reaction has a negative ∆G°, replaces the word “spontaneous” or “spontaneity".”

thermodynamically unfavored

when a reaction has a positive ∆G°