Lecture 5 - Acidity & Equilibria Flashcards
nucleophile:
lewis base (nucleus loving - usually possessing a lone pair of electrons that it can donate)
electrophile:
lewis acid (“electron loving” - there forever must be positively charged or partially positively charged), electron pair acceptor
bronsted acid and bases:
•BrØnsted Acid: A species that donates a H+
•BrØnsted Base: A species that accepts a H+
•A BrØnsted acid-base reaction is an electron-pair displacement reaction on a proton
compounds that can act as either an acid or a base:
amphoteric compounds, with a prime example being water
what is formed when a bronsted acid loses a proton?
when a bronsted acid loses a proton, its conjugate base is formed
what happens when a bronsted base gains a proton?
when a bronsted base gains a proton is becomes a conjugate acid
what strain does Van de Walls repulsion create and what does that encourage?
Van de Walls repulsion creates a torsional strain encouraging rotation towards a more stable conformer - the most stable conformer dominates
what conformations are favoured?
staggered conformer are preferred
what influences conformer populations?
Van de Walls repulsion influences conformer populations
rotation around single bonds:
rotation around single bonds is rapid except at very low temperatures
unit activity state of water:
[H2O] = 1
concentration equilibrium constant =
K = [conc. of product 1] x [conc. of product 2] / [conc. of reactant 1] x [conc. of reactant 2]
pKa =
- log Ka
- log Ka =
pKa
what is pKa?
pKa is a fixed measure of molecular acid strength
