What is the pKa of an amide group?
We also know that, due to resonance with the carbonyl bond, amide nitrogens are not basic (in fact they are very slightly acidic, with a pKa around 20).
What is the pKa of LDA?
Enolates may be formed by reaction with a strong base, such as LDA (lithium diisopropylamide). LDA has a pKa of about 35, which is higher than that for a ketone, ester or nitrile (so will be a stronger base than an enolate). It is non-nucleophilic and does not add to a carbonyl group (at low temperature).
What is pKa of an amine?
The ammonium ions of most simple aliphatic amines have a pKa of about 10 or 11. However, these simple amines are all more basic (i.e., have a higher pKa) than ammonia.
What is the Ka for acetic acid?
Usually Ka very small, ex : Ka for acetic acid = 1.8×10-5 For NH4 + it is 5.6×10-10.
Is LDA a strong base?
NaH and LDA are strong bases.
What is the pKa of a carboxyl group?
The pKa of carboxylic acids typically ~ 5. They are significantly more acidic than water or alcohols.
Which compound has the highest pKa?
HF (pKa = 3.1) , HCl (pKa = -6.0) , HBr (pKa = -9.0) , HI (pKa = -9.5). Hence HF has the highest pKa value.
Why is an amide more acidic than amine?
Amides are more acidic than amines because the nitrogen in the amines has a lone pair of the electrons which accepts protons, whereas, in amides, the amide group and carbonyl groups are bonded together because of high electronegativity of oxygen which makes it get involved in resonance, thus making it either less basic …
What is the K a for a compound with pKa?
pKa and Ka Ka denotes the acid dissociation constant. It measures how completely an acid dissociates in an aqueous solution. The larger the value of Ka, the stronger the acid as acid largely dissociates into its ions.
What is the Ka of acetate?
1.8 * 10-5
|1.8 * 10-5||Ethanoic acid||Ethanoate (acetate) ion|
|4.4 * 10-7||Carbonic acid||Hydrogen carbonate ion|
|1.1 * 10-7||Hydrosulfuric acid||Hydrogen sulfide ion|
|6.3 * 10-8||Dihydrogen phosphate ion||Hydrogen phosphate ion|
What is the pKa of conjugate acids and bases?
Acid strengths decrease down the tablea. Conjugate base strengths increase down the tableb. Name Acid / Conjugate base pKa Sulfuric acid -10 Hydrogen iodide -10 Hydrogen bromide -9 Hydrogen chloride -7 Acetone conjugate acid -7 Benzenesulfonic acid -6.5 Acetic acid conjugate acid -6 Diethyl ether conjugate acid -3.5 Ethanol conjugate acid -2
What are the pKa values for organic and inorganic Bronsted acids?
pKaValues for Organic and Inorganic Bronsted Acids at 25 oC Acid strengths decrease down the tablea. Conjugate base strengths increase down the tableb. Name Acid / Conjugate base pKa Sulfuric acid -10 Hydrogen iodide -10 Hydrogen bromide -9
What is the pKa of the functional groups?
Approximate pKa chart of the functional groups: values to know 1. Protonated carbonyl pKa = ‐7 Other important pKa’s 2. Protonated alcohol or ether pKa = ‐2 to ‐3 H2 = 35 3. Carboxylic acid pKa = 4‐5 4. Ammonium ion pKa = 9‐10 5. Phenol pKa = 10 6.
What is the pKa of acetic acid?
The pKa of acetic acid is 4.76, indicating that this compound will exist partially in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts.