2015年2月1日 · I'll discuss how to determine pH given "pKa" for a monoprotic acid, which is an acid that only donates one proton per molecule when placed in aqueous solution. The general equation for a monoprotic acid in aqueous solution is HA_((aq)) rightleftharpoons H_(aq)^(+) + A_(aq)^(-) If you're dealing with a buffer, then you are dealing with a weak acid. In this case, …

2015年2月1日 · When the pH is lower than the pKa, the species is protonated. Conversely, when the pH is higher than pKa, it's deprotonated. I think you're confused by the way this question is worded. pH is 9.8 pKa of COOH = 2.4 (this means the COOH group is deprotonated and is actually COO-) (they write COOH group b/c that's the convention, I believe).

2008年1月22日 · pKa is a measure of acid strength. It depends on the identity and chemical properties of the acid. pH is a measure of [H+] in a solution. So, if you have a 1 M soln of acid A (pKa = 5) and a 1 M soln of acid B (pKa = 20), soln with acid A …

2007年1月2日 · pH = measures the [H+] ion concentration in an aqueous solution. because of the inverse log relationship to [H+], a higher [H+] indicates a lower pH value, ie. more [H+] = acidic solution. the same applies for pOH except you are measuring [OH-] ions in solution.

2018年5月5日 · The "p"H of a solution is directly related to the "p"K_"a" of a solution via the Henderson-Hasselbach equation, "p"H = "p"K_"a" + log(([A^-])/([HA])) Let's do an example: What is the "p"H of a "1-L" solution of 0.12"M" of NH_4Cl to which "1 L" of 0.03"M" of NaOH was added ("p"K_"a" of NH_4^(+) is 9.25^([1]))?# Consider the equilibrium, NH_4^(+) + OH^(-) …

2014年9月11日 · pH=pKa+log[A-]/[HA] Which is to say, given a pH and the pKa of the group of interest, you can set the equation up and have it look like this: pH=pKa+log(X) where X represents the ratio of deprotonated to protonated species. So you can rearrange and get 10^-(pH-pKa)=X At least that's how I did it.

2014年1月29日 · Only the C-terminal, N-terminal, and R-groups will participate in ion exchange. Since the imidazole group on histidine has a pKa of 6.0, a solution with a pH of 7 will favor the negative ion on the functional group of histidine.

2016年3月25日 · pH = pK_a + log_10{[[A^-]]/[[HA]}} Consider the general acid dissociation reaction in water: HA(aq) + H_2O(l) rightleftharpoons H_3O^+ + A^-. Now, this is an equilibrium reaction, and for a given temperature, we can write the equlibrium expression: K_a=([H_3O^+][A^-])/([HA]). This is an equation, and like any equation we can add/subtract/multiply it etc. and …

2018年3月23日 · "pH" is the negative logarithm of the concentration of protons in solution as a result of dissolving the acid. pK_"a" is the negative logarithm of the equilibrium expression of the acid dissociating. HA rightleftharpoons H^(+) + A^(-), where K_a = ([H^+][A^-])/([HA]) To be sure, if the subject of each "power" is high, then it is consequently low in magnitude. Thus, if …

2015年8月7日 · This is a form of the buffer equation, with which you are going to get very familiar. Now at half-equivalence, by definition, [HA] = [A^-], and since log_10 1 = 0, when plugged back into the equation, pH = pK_a. So, in order to measure pK_a values of weak acids we plot a titration curve with a pH meter, and note value at half-equivalence.