A 1.00-g sample of piperazine hexahydrate is dissolved in enough water to produce 100.0 mL of...

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Chemistry

A 1.00-g sample of piperazine hexahydrate is dissolved in enoughwater to produce 100.0 mL of solution and is titrated with 0.500M HCl.
A.) What is the initial pH of the solution, before any titrantis added?
B.) The percent neutralizationpoints for a titration indicate the percent of the reagent that hasreacted. For example, at the 25% neutralization point forpiperazine, 75% (0.75Ã—[Pip]) of the base remains, and 25% isneutralized to form PipH+.
Calculate the pH at the 25%, 50%, and 75% neutralization pointsof the first neutralization, respectively.
C.) What is the pH at the first equivalence point?
D.) The percent neutralizationpoints for a titration indicate the percent of the reagent that hasreacted. For example, at the 25% neutralization point for PipH+,75% (0.75Ã—[PipH+]) of the base remains, and 25% is neutralized toform PipH22+.
Calculate the pH at the 25%, 50%, and 75% neutralization pointsof the second neutralization, respectively.
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4.1 Ratings (635 Votes)

Molar mass for piperazine19424 gmole 100 g Pip 119424 000515 moles Pip Molarity 000515 100 1000 00515 M pKb1 Pip 422 Kb1 60 x 105 pKb2 Pip 867 Kb2 21 x 109 a Molarity Pip H2O PipH OH Initial 00515 0 0 Change x x x Equilibrium 00515x x x Kb1 PipHOH Pip xx 00515x 60 x 105 As Kb1 is small ignore the x term after 00515 to simplify the math x2 00515 60 x 105 x2 31 x 106 x 18 x 103 M OH pOH log OH log 18 x 103 275 pH 1400 pOH 1400 275 1125 b During the first See Answer

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