A Sapling Learning Map Colculate the volume, in liters, of 1.565 M KoH that must

Question

A Sapling Learning Map Colculate the volume, in liters, of 1.565 M KoH that must be added to a o 112 L solution containing 986 g of glutamic acid hydrochloride (H3Glu ch, Mw 183.59 g/mol) to achieve a pH of 10.26. Glutamic acid (Glu) is an amino acid with pKa values of pKat 2.23, pKa2 4.42, pKa3 9.95. Number NH3 H CH2-CH2 Glutamic Acid Hydrochloride A Previous e Check Answer o Next Exit r Hint Glutamic hydrochloride cr) the fully protonated, acidic form of the triprotic amino acid glutamic The desired 10.26 is greater than pKa3 of glutamic acid, which indicates the solution contains a mixture of the intermediate form HGlu and the completely deprotonated form Glu2- Since the initial solution contains o H3GIu', enough KoH must first be added to H HzGlu convert all of the to give the and then HGlu Additional KoH must then be added to create a mixture of HGlum and desired pH.

Explanation / Answer

Molar concentration of glutamic acid = grams/molar mass x volume of solution

                                                          = 9.86/183.59 x 0.112

                                                          = 0.48 M

moles of glutamic acid = 0.48 M x 0.112 L

                                     = 0.054 mols

let x moles of KOH has been added

using hendernsen-hasselbalck equation,

pH = pKa + log(base/acid)

10.26 = 9.95 + log(x/0.054-x)

x = 0.1102 - 2.042x

x = 0.036 mols

volume of KOH requred to be added = moles/molarity

                                                           = 0.036/1.565

                                                           = 0.023 L

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