Hello, want to locate a value from an pH array when closest to 4.756 and then locate the corresponding Vb value associated with that pH value. Any help would be appreciated. See last 2 lines.
format short Kw = 1e-14; Ka = 1.755388e-5; pKa = 4.756; %
Ca = 0.5; Cb = 0.1; Va = 100; Vb = 0.05:0.05:2000; Ma = (Ca * Va) / 1000; Mb = (Cb .* Vb) ./ 1000; for i = 1:length(Mb) M_excess = Ma - Mb(i); if abs(M_excess)<eps Hplus = Ka * ((Ma_final * 0.999999) ./ Mb_final); Vb_ev = Vb(i); pH_ev = pH(end); elseif M_excess > 0 Ma_final = (M_excess * 1000) ./ (Va + Vb(i)); Mb_final = (Mb(i) * 1000) ./ (Va + Vb(i)); Hplus = Ka * (Ma_final ./ Mb_final); elseif M_excess < 0 OH = (M_excess * 1000 * (-1)) ./ (Va + Vb(i)); Hplus = Kw ./ OH; end pH(i) = -log10(Hplus); end %
pH_Mid_Pt2 = find pH value when closest to 4.756; Vb_Mid_Pt2 = find corresponding Vb value at pH_Mid_Pt2;
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