Примери коришћења Pka на Енглеском и њихови преводи на Српски
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The enol proton has a pKa value of 13.02.
The pKa for the equilibrium is not well characterized.
This acidity can differ by 5 pKa units.
If pH is below the pKa value, the converse is true.
HSO3- is a weak acidic species with a pKa of 6.97.
H2CrO4⇌-+ H+ The pKa for the equilibrium is not well characterized.
It is a weak acid with a pKa of 9.2.
Typical pKa values are 16.7 for acetaldehyde and 19 for acetone.
The drugs characteristics, including its pKa.
A weak acid has a pKa value in the approximate range- 2 to 12 in water.
Malononitrile is relatively acidic, with a pKa of 11 in water.
A weak acid has a pKa value in the approximate range- 2 to 12 in water.
In the reduced form of plastocyanin,His-87 will become protonated with a pKa of 4.4.
As a result, its pKa is 13.6 meaning that guanidine is a very strong base in water.
This new concept builds on earlier ideas and it depends on a number of distinct factors: The drugs characteristics,including its pKa.
Mycophenolate mofetil is reported to have a pKa values of 5.6 for the morpholino moiety and 8.5 for the phenolic group.
The pKa of a compound is determined by many things, but the most significant is the stability of the conjugate base.
An equilibrium that is much more consistent with spectroscopic evidence is given:SO2+ H2O⇌ HSO3-+ H+ HSO3- is a weak acidic species with a pKa of 6.97.
Aziridine is less basic than acyclic aliphatic amines, with a pKa of 7.9 for the conjugate acid, due to increased s character of the nitrogen free electron pair.
Phosphines are often less basic than corresponding amines,for instance the phosphonium ion itself has a pKa of- 14 compared to 9.21 for the ammonium ion;
The N-H center has a pKa of 21 in DMSO, so that very strong bases such as sodium hydride or n-butyl lithium and water-free conditions are required for complete deprotonation.
It indicates the acidity in the ECF in an inverse manner:the lower the pH the greater the acidity of the solution. pKa H2CO3 is the cologarithm of the acid dissociation constant of carbonic acid.
Electron withdrawing groups(which can stabilize the molecule by increasing charge distribution) or electron donating groups(which destabilize by decreasing charge distribution)present on a molecule also determine its pKa.
The reactivity is enhanced when the thiol is ionized, and cysteine residues in proteins have pKa values close to neutrality, so are often in their reactive thiolate form in the cell.
Because the range of possible values forKa spans many orders of magnitude, a more manageable constant, pKa is more frequently used, where pKa=- log10 Ka.
The properties of H2S and H2Se are similar, although the selenide is more acidic with pKa= 3.89, and the second pKa= 15.05± 0.02 at 25 °C. Reflecting its acidity, H2Se is soluble in water.
Because of resonance stabilization of the conjugate base, an α-hydrogen in an aldehyde(not shown in the picture above)is far more acidic, with a pKa near 17, than a C-H bond in a typical alkane(pKa about 50).
Phosphines are often less basic than corresponding amines,for instance the phosphonium ion itself has a pKa of- 14 compared to 9.21 for the ammonium ion; trimethylphosphonium has a pKa of 8.65 compared to 9.76 for trimethylammonium.
Because of resonance stabilization of the conjugate base, an α-hydrogen in an aldehyde(not shown in the picture above)is far more acidic, with a pKa near 17, compared to the acidity of a typical alkane(pKa about 50).