Question

EDTA is a hexaprotic system with the pK, values: pKal = 0.00, pKa2 = 1.50, pKa3 = 2.00, pK24 = 2.69, pKa5 = 6.13, and pKa6 = 10.37. The distribution of the various protonated forms of EDTA will therefore vary with pH. For equilibrium calculations involving metal complexes with EDTA, it is convenient to calculate the fraction of EDTA that is in the completely unprotonated form, Y4-. This fraction is designated Aye-. TOOC—CH2 H C—Coo :N-CH2-CH2-N: -ooc-CH2 H₂c_coo EDTA4- (or Y4-) Calculate Qy4- at two pH values. pH = 3.55 Qy4- = | 3.40 x10-11 pH = 10.25 Qyt- =

Answer 1

Hi this is very high calculation part and the formula we have to use is shown below.

pH = 3.55 ==> [H⁺] = 10^-pH = 10^-3.55 = 0.00028183829

pH = 10.25 ==> [H⁺] = 10^-pH = 10^-10.25 = 5.6234133e-11

pK1 = 0.00 ==> K₁ = 10^-pK1 = 10^-0.000 = 1

pK2 = 1.50 ==> K₂ = 10^-pK2 = 10^-1.5 = 0.0316227766

pK3 = 2.00 ==> K₃ = 10^-pK3 = 10^-2.00 = 0.01

so..on…..substituting these values into below formula

Question 1 of 5 EDTA is a hexaprotic system with the following pka values: CH2-C0o- Map dat pka1 = 0.00 pka2 = 1.50 pk 2 = 2.00 pK24 = 2.69 pka5 = 6.13 PK 6 = 10.37 Tooc-CH2 N-CH2-CH2-R OOC-CH2 CH2-COO EDTA4 (or Y4-) me distribution of protonated forms of EDTA will therefore vary with PH. For equilibrium calculations involving metal complexes with EDTA, it is convenient to calculate the fraction of EDTA that is in the completely unprotonated form, Y- (see the figure). This fraction is designated art. Calculate ay- at the following two pH values: pH = pH = Number Number a = a Hint Previous Give Up & View Solution Check Answer Next Exit The following expression is used to calculate ay- art- K,K,K,K,K,K [H*]+ [*]*x, + [h*]*K,K,+ (H * ]'K,K,K,+ [h*]K,K,K,K,+ [H*]K,K,K,K,K,+ K,K,K,K.KKO

at pH = 3.55 the value of α_Y4- = 3.47815E-10

at pH = 10.25 the value of α_Y4- = 0.431340003

EDTA is a hexaprotic system with the pK, values: pKal = 0.00, pKa2 = 1.50, pKa3 = 2.00, pK24 = 2.69, pKa5 = 6.13, and pKa6 = 10.37. The distribution of the various protonated forms of EDTA will therefore vary with pH. For equilibrium calculations involving metal complexes with EDTA, it is convenient to calculate the fraction of EDTA that is in the completely unprotonated form, Y4-. This fraction is designated Aye-. TOOC—CH2 H C—Coo :N-CH2-CH2-N: -ooc-CH2 H₂c_coo EDTA4- (or Y4-) Calculate Qy4- at two pH values. pH = 3.55 Qyt = 3.478E-10 pH = 10.25 Qy4- = 0.4313

Hope this helped you!

Thank You So Much! Please Rate this answer as you wish.("Thumbs Up")