Organic Chemistry - Values

~50

What is the pka of this molecule (methane)

~15

What is the pka of this molecule (water)

~35

What is the pka of this molecule (ammonia)

~4

What is the pka of this molecule (hydrofluoric acid)

~5

What is the pka of this molecule (carboxylic acids)

~10

What is the pka of this molecule (phenols)

~16

What is the pka of this molecule (alcohols)

~35

What is the pka of this molecule (amines)

44

What is the pka of this molecule (alkene)

25

What is the pka of this molecule (alkyne)

~35

What is the pka of this molecule (hydrogen)

~43 (note how close this value is to that of C2H4, another alkene, but with the bond next to the double bond)

What is the pka of this molecule

~20

What is the pka of this molecule (ketone)

~25

What is the pka of this molecule (ester)

~30 (unless R=H, which would make the N-H bond the most acidic pka= 10-15)

What is the pka of this molecule (amides)

~10

What is the pka of this molecule (thiols)

~15 for the alcohol, ~10 for the thiol (polarizability due to the size of the sulfur atom plays a big role here)

How do the pka values of these molecules differ?

~15 for the alcohol, ~10 for the phenol (resonance hybridization plays a big role here)

How do the pka values of these molecules differ?

~50 for the alkane, ~44 for the alkene, ~25 for the alkyne (hybridization plays a big role here)

How do the pka values of these molecules differ?

~35 for ammonia, ~31 for the alkene, -10 for the alkyne (charge is the cause of the unexpectedly low pka value)

How do the pka values of these molecules differ?

~5

What is the pka of this molecule?

Left: ~2.5 Right: ~3 (Fluorine is more electronegative than Chlorine which results in a stronger inductive effect)

How do the pka values of these molecules differ?

Left: ~5, Middle: ~3, Right: ~4. (the inductive effects of chlorine were affected by the distance from the H bond of intrest)

How do the pka values of these molecules differ?

Carboxylate / Acetate Ion

Name a base with a pka of 5

Amines

Name a base with a pka of 10

Hydroxide or Methoxide

Name a base with a pka of 15

Amide Ions (R2N-) and Hydrides (H-)

Name a base with a pka of 35

Methenium (methyl cation)

Name a base with a pka of over 60

17 (this applies only to the H directly attached to the C=O. Protons further from the aldehyde have very high pka values, similar to amides)

What is the pka of this molecule (aldehyde)

~9 (9.25)

What is the pka of this molecule (ammonium)

~9 (closest H to nitro group)

What is the pka of this molecule (nitro)