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With pOH obtained from the pOH formula given above, the pH of the base can then be calculated from =, where pK w = 14.00. A weak base persists in chemical equilibrium in much the same way as a weak acid does, with a base dissociation constant (K b) indicating the strength of the base. For example, when ammonia is put in water, the following ...
pKa values for acetic, chloroacetic, dichloroacetic and trichloroacetic acids. Inductive effects and mesomeric effects affect the pK a values. A simple example is provided by the effect of replacing the hydrogen atoms in acetic acid by the more electronegative chlorine atom.
Like all anion exchangers, the resin carries a positive charge that interacts favorably with negative charges. The positive charge of DEAE cellulose is due to a protonated amine group. To ensure that the resin is protonated and positively charged, the chromatography should be performed at least 2 pH units below the pKa of the amine group, 10.
When dissociated, the diisopropylamide anion can become protonated to form diisopropylamine. Diisopropylamine has a p K a value of 36. Therefore, its conjugate base is suitable for the deprotonation of compounds with greater acidity, importantly, such weakly acidic compounds (carbon acids) of the type HC(Z)R 2 , where Z = C(O)R', C(O)OR' or CN.
The negative charges create a repulsion that causes the polymer to swell. This swelling behavior is observed when the pH is greater than the pKa of the polymer. [ 2 ] Examples include polymethyl methacrylate polymers (pharmacologyonline 1 (2011)152-164) and cellulose acetate phthalate.
In computational biology, protein pK a calculations are used to estimate the pK a values of amino acids as they exist within proteins.These calculations complement the pK a values reported for amino acids in their free state, and are used frequently within the fields of molecular modeling, structural bioinformatics, and computational biology.
On the same day that the Centers for Disease Control and Prevention eased COVID-19 guidelines, the Food and Drug Administration issued a statement warning that at-home rapid antigen tests can ...
Lithium chloride is a chemical compound with the formula Li Cl.The salt is a typical ionic compound (with certain covalent characteristics), although the small size of the Li + ion gives rise to properties not seen for other alkali metal chlorides, such as extraordinary solubility in polar solvents (83.05 g/100 mL of water at 20 °C) and its hygroscopic properties.