Piperazine is a diprotic weak base used as a corrosion

Chapter 17, Problem 78

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Piperazine is a diprotic weak base used as a corrosion inhibitor and an insecticide. Its ionization is described by the following equations. The piperazine used commercially is a hexahydrate, A 1.00-g sample of this hexahydrate is dissolved in 100.0 mL of water and titrated with 0.500 M HCl. Sketch a titration curve for this titration, indicating (a) the initial pH; (b) the pH at the halfneutralization point of the first neutralization; (c) the volume of HCl(aq) required to reach the first equivalence point; (d) the pH at the first equivalence point; (e) the pH at the point at which the second step of the neutralization is half-completed; (f) the volume of 0.500 M HCl(aq) required to reach the second equivalence point of the titration; (g) the pH at the second equivalence point.