Module 3: ACIDS AND BASES Flashcards
can have different
meanings in different contexts
“acid” and “base”
The idea that acids are solutions containing a lot of “H+” and bases are solutions containing a lot of “OH-” is not very useful in organic chemistry
ARRHENIUS THEORY
defines
acids and bases by their role in reactions that “transfer protons” (H+) between “donors” and “acceptors”
Brønsted–Lowry theory
donates a H+
(proton donor)
Brønsted acid
accepts the H+
(proton acceptor)
Brønsted base
The products of proton transfer reaction are called?
conjugate base and
conjugate acid
electron pair acceptors
Lewis acids
electron pair donors
Lewis bases
A measure related to the strength of the acid:
HA -> H+ + A-
Acidity constant (Ka)
Stronger acids have
larger Ka
The concentration of ______ as a solvent does not change significantly when it is protonated
water
Ka of water
1.8 x 10-16
Ka= about 10^15
strongest acids
Ka = about 10^-60
weakest acids
the Acid Strength Scale
pKa
Formula of pKa
pKa = –log Ka
Ka = antilog (- pKa) = 10-pKa
Smaller pKa -> larger Ka -> ??
stronger acid
The pKa of water
15.74
presence of “positively polarized H atom”
ORGANIC ACIDS
those that lose a proton from “O–H”, such as methanol and acetic acid
ORGANIC ACIDS
those that lose a proton from “C–H”, usually from a carbon atom next to a C=O double bond (O=C–C–H)
ORGANIC ACIDS
have an atom with a lone pair of electrons that can bond to H+
ORGANIC BASES
Nitrogen-containing compounds derived from ammonia are the most common organic bases
ORGANIC BASES
Oxygen-containing compounds can react as bases when with a strong acid or as acids with strong bases
ORGANIC BASES
can react as bases when with a strong acid or as acids with strong bases
Oxygen-containing compounds
derived from ammonia are the most common organic bases
Nitrogen-containing compounds
