Carboxylic Acids - Chp 20 Flashcards
Increasing stability of the C.B, increases what? Smaller or lower pKa?
The acidity; Smaller pKa
Does resonance always increase stability of C.B?
No, not always, it depends on the location of the anion.
Electron-withdrawing groups ________ C.B, making carboxylic acid _______ acidic
stabilize; more
Electron donating groups __________ C.B, making carboxylic acid _______ acidic.
destabilize; less
Electron-withdrawing groups ________ the acid strength, and electron-donating groups _________ the acid strength.
enhance; decrease
What effects are strongest for substituents positions?
Ortho and para positions.
(ortho > para with the same substituent)
Oxidation of alcohol and aldehyde with what reagent produces a carboxylic acid.
Chromic acid (H2CrO4) or NaOCl
Naming a carboxylic acid involves removing the āeā from an alkane/alkene and adding ____.
-oic acid
Compounds containing 2 carboxy groups are called what?
Diacids
ex. ethanedioic acid
For naming metal salts what suffix do you add?
-ate
ex. sodium propanate
The high boiling points of carboxylic acids result from what?
The formation of a stable,
hydrogen-bonded dimer.
Do double bonds increase or decrease the melting point? Does cis or trans affect it more?
Decrease; especially cis
Acids with more than 10 carbon atoms are nearly __________ (soluble/insoluble)
insoluble.
Which is more stable between acetate ion and alkoxide ion? Why?
Acetate ion because the delocalization of the negative charge over the two oxygens makes it more stable than an alkoxide ion.
Having the negative charge on C instead of O is less or more stable? Why?
Less stable b/c C is less electronegative.
What 3 things can make an acid stronger?
Increase number of electronegative substituents, the more electronegative substituent (compared to another atom), the closer the electron withdrawing group to the COOH.
Primary alcohol, aldehyde and H2CrO4 produces what?
Carboxylic acid
Cleavage of an alkene with hot KMnO4 produces a carboxylic
acid with what reagent is present?
A vinylic hydrogen present
Primary alcohol or aldehyde with what reagent produces a carboxylic acid?
Na2Cr2O7, H2SO4
Ozonolysis of an alkyne produces what? What reagents are used?
A carboxylic acid group; conc. KMnO4 or 1. O3 2. H2O
Alkyl benzenes with KMnO4 and heat produces what?
Benzoic acid.
Alkene with hot KMnO4 and a vinylic hydrogen produces what?
A carboxylic acid and a ketone.
How to produce a carboxylic acid from an alkyl or aryl halide?
With a Grignard reagent, CO2 and H+
A nitrile reacting with what reagent produces a carboxylic acid?
H+, H2O or OH- (Hydrolysis)
Reaction of a carboxylic acid with _______ under acidic conditions produces an ester. (Fisher Esterification)
alcohol
True or false. Esterification of a carboxylic acid occurs in the presence of acid but not in the presence of base.
True, only the presence of acids (not bases like OH-)
How are carboxylic acids converted to methyl esters?
By adding/reacting with diazomethane(N=N=CH2).
LiAlH4 and H3O+ reduces carboxylic acids to ________.
primary alcohols
Borane (BH3.THF) can reduce a __________ to _________.
a carboxylic acid; alcohol
What reagent is used to convert COOH to a ketone?
2R-Li and H2O
ex. CH3CH2-Li and H2O
Are alcohol soluble?
Yes, very soluble.
As the length of the carbon chain increase, water solubility _______.
decreases
What reagent is used to convert a carboxylic acid to an acid chloride?
SOCl2 or C2O2Cl2
Carboxylic acid reacting with SOCl2 produces __________.
An acid choride.
