What volume, in liters, of 1.04 M KOH solution should be added to a 0.116 L solution containing 10.08 g of glutamic acid hydrochloride (Glu, FW = 183.59 g/mol; pKa1 = 2.23, pKa2 = 4.42, pKa3 = 9.95) to get to pH 10.15?
Is my Henderson equation right? 10.15=9.95+log(x/(.059-x))
It looks ok except for the 0.059.
10.08/183.59 = 0.0549 mols
Thanks!
To find the volume of 1.04 M KOH solution needed, we will use the concept of acid-base titration. Given that we have a pH value and the concentration of the KOH solution, we can calculate the volume needed to reach the desired pH.
Here is the step-by-step process to solve the problem:
1. Calculate the number of moles of glutamic acid hydrochloride (Glu) in the solution:
Given mass of Glu = 10.08 g
Molecular weight of Glu = 183.59 g/mol
Number of moles of Glu = mass / molecular weight
Number of moles of Glu = 10.08 g / 183.59 g/mol
2. Calculate the concentration of Glu in the solution:
Given volume of solution = 0.116 L
Concentration of Glu = number of moles / volume
Concentration of Glu = (10.08 g / 183.59 g/mol) / 0.116 L
3. Determine the molar ratio between KOH and Glu:
The balanced equation for the reaction between KOH and Glu is:
KOH + Glu → KGlutamate + H2O
From the equation, the molar ratio between KOH and Glu is 1:1.
4. Calculate the number of moles of KOH needed to reach pH 10.15:
Since Glu is a polyprotic acid, it can lose multiple protons. To find the amount of KOH needed to reach pH 10.15, we need to determine the moles of Glu that are protonated and need to be neutralized.
From the pKa values given, we can determine that Glu will be mostly deprotonated at pH 10.15. Therefore, we can assume that Glu is in its deprotonated form.
5. Determine the volume of 1.04 M KOH solution needed:
Now we can calculate the volume of the 1.04 M KOH solution required to neutralize the Glu and reach pH 10.15.
Volume of KOH solution = number of moles of KOH / concentration of KOH
Volume of KOH solution = (number of moles of Glu × 1) / 1.04 M
Ensure that the units cancel appropriately, and you should be left with the volume in liters.
By following these steps, you can find the volume of 1.04 M KOH solution needed to reach pH 10.15.