Chem 203 Dr. Weinschenk pKa Table

Comprehensive vocabulary flashcards covering acid names, pKa values, conjugate base identities, and structural notes from the Chem 203 Dr. Weinschenk pKa Table.

Hydroiodic Acid ($HI$)

The strongest acid on the table with a $pKa$ of $-10$, whose conjugate base is the iodide anion ($I^-$).

Hydrobromic Acid ($HBr$)

A strong hydrohalic acid with a $pKa$ of $-9$, forming the bromide anion ($Br^-$) as its conjugate base.

Hydrochloric Acid ($HCl$)

A strong hydrohalic acid with a $pKa$ of $-7$, whose conjugate base is the chloride anion ($Cl^-$).

Protonated Alcohol ($ROH_2^+$)

An oxonium acid with a $pKa$ of $-3$, which deprotonates to give an alcohol ($ROH$) conjugate base.

Sulfuric Acid ($H_2SO_4$)

A strong diprotic mineral acid with a $pKa$ of $-3$, yielding the hydrogen sulfate anion ($HSO_4^-$) as its conjugate base.

p-Toluenesulfonic Acid ($TsOH$)

A strong organic sulfonic acid with a $pKa$ of $-3$ , which deprotonates to form the tosylate conjugate base.

Hydronium Ion ($H_3O^+$)

The hydrated proton acid species with a $pKa$ of $-1.7$ , whose conjugate base is neutral water ($H_2O$).

Nitric Acid ($HNO_3$)

A strong mineral acid whose deprotonation yields the resonance-stabilized nitrate anion ($NO_3^-$). pka= -1.4

Phosphoric Acid ($H_3PO_4$)

A triprotic acid characterized by stepwise $pKa$ values of $2.12$, $7.21$, and $12.32$, forming dihydrogen phosphate ($H_2PO_4^-$) upon initial deprotonation.

Hydrofluoric Acid ($HF$)

A weak hydrohalic acid with a $pKa$ of $3$, whose conjugate base is the fluoride anion ($F^-$).

Carboxylic Acid ($RCOOH$)

An organic acid class with a $pKa$ of $4$, whose conjugate base is a resonance-stabilized carboxylate anion ($RCOO^-$).

Hydrazoic Acid ($HN_3$)

An inorganic acid with a $pKa$ of $4.6$, which forms the azide anion ($N_3^-$) as its conjugate base.

Hydrogen Sulfide ($H_2S$)

A diprotic sulfur acid with a $pKa$ of $7$, whose conjugate base is the hydrogen sulfide anion ($HS^-$).

$\beta$-Dicarbonyl

A compound with a $pKa$ of $9$, whose conjugate base benefits from "double" resonance stabilization between two flanking carbonyl groups.

Ammonium Ion ($NH_4^+$)

A positively charged nitrogen acid with a $pKa$ of $9.25$, whose conjugate base is ammonia ($NH_3$).

Hydrogen Cyanide ($HCN$)

A weak acid with a $pKa$ of $10$, which deprotonates to give the cyanide anion ($CN^-$).

Phenol

An aromatic alcohol with a $pKa$ of $10$, whose conjugate base is the phenoxide anion.

Bicarbonate ($HCO_3^-$)

An oxyanion acid with a $pKa$ of $10.2$, which deprotonates to form the carbonate anion ($CO_3^{2-}$).

Thiol ($RSH$)

A sulfur-containing organic compound with a $pKa$ of $12$, forming a thiolate conjugate base ($RS^-$).

Cyclopentadiene

A cyclic hydrocarbon with an unusually low $pKa$ of $16$ because its deprotonation produces an aromatically stabilized conjugate base.

Amide ($H_3C-CONH_2$) (look arrow)

An amide compound with a $pKa$ of $15$, whose deprotonation yields an amidate anion ("nitrogen enolate").

Water ($H_2O$)

A neutral amphoteric molecule with an acid $pKa$ of $15.7$, whose conjugate base is the hydroxide anion ($HO^-$).

Alcohol ($ROH$)

An organic hydroxy compound with a $pKa$ of $17$, which deprotonates to form an alkoxide conjugate base ($RO^-$).

Aldehyde ($R-CHO$)

A carbonyl compound having an $\alpha$-hydrogen with a $pKa$ of $17$, yielding an enolate conjugate base.

Ketone ($RCOCH_3$)

A carbonyl compound having an $\alpha$-hydrogen with a $pKa$ of $19$, yielding an enolate conjugate base.

Chloroform ($HCCl_3$)

A haloalkane with a $pKa$ of $15$ , whose conjugate base is the trichloromethyl anion ($CCl_3^-$).

Esters ($H_3C-COOR$)

Carboxylic acid derivatives with an $\alpha$-carbon $pKa$ of $24$, forming an ester enolate conjugate base.

Acetylene ($RC \equiv CH$)

A terminal alkyne with an $sp$-hybridized carbon $pKa$ of $24$, forming an acetylide anion ($RC \equiv C^-$).

Tertiary Amide ($H_3C-CONR_2$)(look arrow)

An amide whose $\alpha$-carbon hydrogens possess a $pKa$ of $25$, deprotonating to form an amide enolate.

Acetonitrile ($H_3C-CN$)

A nitrile compound with a $pKa$ of $25$, whose deprotonation gives the conjugate base $H_2C-CN^-$.

Molecular Hydrogen ($H_2$) (hydride)

A diatomic gas with a $pKa$ of $35$, whose deprotonation forms the hydride anion ($H^-$).

Ammonia ($NH_3$)

A neutral nitrogen hydride with a $pKa$ of $35$, whose conjugate base is the strongly basic amide anion ($NH_2^-$).

Benzene

An aromatic hydrocarbon with a $pKa$ of $43$, forming the phenyl anion upon deprotonation.

Propene (Allylic C-H)

A hydrocarbon with an allylic $pKa$ of $43$, which upon deprotonation produces the resonance-stabilized allyl anion.

Ethylene ($H_2C=CH_2$)

An alkene with a $pKa$ of $45$, whose conjugate base is the vinyl anion ($H_2C=CH^-$).

Methane ($CH_4$)

A saturated alkane with a $pKa$ of $48$, which deprotonates to give the methyl anion ($CH_3^-$).

Isobutane ($(CH_3)_3CH$)

The weakest acid on the table with a $pKa$ of $65$, whose conjugate base is the strongest base.

Cyclopropane C3H6

pKa=45