Chapter 2 Flashcards
(19 cards)
what are resonance structures?
valence bond representations of possible distribution of ELECTRONS in a molecule
What do major resonance forms contain(4)?
- has as many octets as possible
- has as many bonds as possible
- has the negative charge on the most electronegative atom
- has as little charge separation as possible
which compounds act as a bronsted lowry acid?
ANY compound containing hydrogen atoms
is is Ka?
acid dissociation constant
What is the definiton of lewis acid and bases? which are nucleophiles and which are electrophiles?
acids accept pairs=electrophile
bases
-bases donate electron pairs=nucleophile
What are the only two ways resonance structures differ?
in the placement of their pi bonds or nonbonding electrons
How do we know which is the most stable resonance form?
the form with the negative charge on the most electronegative atom
How to find conjugate acid and base?
conjugate acid is product of acid losing a proton and conjugate base is product of base gaining a proton
what kind of base does a strong acid have?
a weak base
what kind of base does a strong acid have?
strong conjugate base
does pka value increase or decrease with increasing acid strength?
decrease
what does h+ always going FROM the stonger acid to the weaker base mean in terms of acid and base strength?
an acid will donate a proton to the conjugate of a weaker acid and the conjugate base of a weaker acid will remove a proton from a stronger acid
do carboxylic organic acids(compounds containing the -CO2H grouping) usually accept or donate a proton?
donate
what does it look like before compared to after the reaction in terms of proton transfer?
the structure of the stronger acid will have one LESS hydrogen in the structure after the reaction and the structure of the weaker acid will have one MORE hydrogen after the reaction
compounds containing what element are almost always bases?
nitrogen
are compounds containing oxygen usually acids or bases?
they can act as either- as base when reacting with a very strong acid
how do you know which structure is formed from an acid base reaction if there are multiple sites where protonation can occur(ie more than one atom with a lone pair of electrons)?
the structure that is more stable, which is the structure that is stabilized by two resonance forms
What atoms form hydrogen bonds?
Oxygen and Nitrogen
what is a condensed structure?
lists grouping in order of bonding but does not include bonds or lone pairs
