is pka the negative log of ka?
157938
pKa is simply negative one times log base 10 of Ka. This is done just to make the numbers easier to work with, the same way we tend to talk about acidity in terms of pH rather than [H+].
1117027
log (1/a) = -log a means that the logarithm of 1 divided by some number is equal to the negative logarithm of that number. (This is the exactly the opposite of the rule governing exponents where a number raised to a negative number is equal to 1 divided by that number raised to that power.)
813217
The weakest acid has the smallest Ka. In this problem that would be (D) HCN. In general, the more positive the pKa is, the weaker the acid.
817526
Why is the KL divergence always non-negative? An important property of the KL divergence is that it's always non-negative, i.e. DKL(P || Q) ≥ 0 for any valid P, Q.
926
The reason pKa is used is because it describes acid dissociation using small decimal numbers. The same type of information may be obtained from Ka values, but they are typically extremely small numbers given in scientific notation that are hard for most people to understand.
1301937
The stronger an acid, the greater the ionization, the lower the pKa, and the lower the pH the compound will produce in solution. ... Since organic reactions can be performed in non-aqueous environments, the pH can exceed 14 and organic compounds can have pKa values above 16.
1173087
Acids are neutral when protonated and negatively charged (ionized) when deprotonated. Bases are neutral when deprotonated and positively charged (ionized) when protonated. Given the information you provided, if compound A (with pKa 7.9) is in a solution of pH 5.2, compound A will be in the protonated state.
1077779
ΔH is negative and ΔS is positive. This condition describes an exothermic process that involves an increase in system entropy. In this case, ΔG will be negative regardless of the temperature. Such a process is spontaneous at all temperatures.
560684
Cpk can only have positive values. It will equal zero when the actual process average matches or falls outside one of the specification limits. The Cpk index can never be greater than the Cp, only equal to it. This happens when the actual process average falls in the middle of the specification limits.
1233819
Relationship between Ka, pKa and acid strength: The smaller the value of Ka, the larger the value of pKa, the weaker the acid. If the pH of a solution of a weak acid and the pKa are known, the ratio of the concentration of the conjugate base to the concentration of the acid may be calculated.
1020310
The pKa value is a negative logarithm, which means when the equation -log x = y is reversed, x is equal to a negative exponent 10-y, which is a small number if y is large and a large number if y is small.
607353
Yes, it is possible for Cpk and Ppk to be negative. ... It is impossible to have a standard deviation be negative so that would mean that x(bar) was larger that the Specification Limit. In other words, the process average is out of specification.
336813
A knowledge of the ionization constants (pKa) of compounds is important for much of the work carried out in the drug discovery process. ... Notably, compounds in their unionized form tend to be less soluble but can more easily penetrate lipophilic barriers existing between them and a biological target of interest.
613256
A large Kb value means a base has largely dissociated and indicates a strong base. A small pKb value indicates a strong base, while a large pKb value indicates a weak base. pKa and pKb are related using a simple equation: pKa + pKb = 14.
901224
A: Yes, there is negative marking in XAT. For each wrong answer 0.25 marks will be deducted.
261646
The lower the pKa, the stronger the acid and the greater its ability to donate protons. pH depends on the concentration of the solution. This is important because it means a weak acid could actually have a lower pH than a diluted strong acid. ... On the other hand, the pKa value is constant for each type of molecule.
107538
point are the same. Therefore, at the half-equivalence point, the pH is equal to the pKa. A plot of the titration curve allows the equivalence point to be determined. At exactly one- half the volume of the equivalence point, the measured pH is equal to pKa as illustrated in Figure 3.