試題詳解

複選題
9. Which of the follow lowing state stements about alpha val lue is (are) correct? (AB) The reiative e equilibrium concea ntrations of the components in a conjugate system (e.g. a conjugate acid/base) are called slipha (a) values. (AC) The alpha values of a conjugate ncid/base depend on pH and K_a. (AD) Tbe alpha values of a conjugate acid/base are independent of the sum of the analytical concontrations of the acid and its conjugate base in a buffer solution. (AE) Plotting the alpha values as a function of the pH of the solution shows curves crossing at pH-pK_b, wihere K_b i₃ the base dissociation constant of the conjugate base, (BC)Since EDTA is a polyprotic acid, its alpha values affect the complex fornation between EDTA and the metal ion (ABE). (BD) Decreasing the o4 value of EDTA favors the fornation of the EDTA-M complex.