Ionization Constant of Weak Acid.docx - Penn State...

Penn State Brandywine
Lab #4 Ionization Constant
DATA SHEET
NAME _Maria Englert_ PARTNER _Mikaylin Sutton____
Titration of Standardized HCl with Standardized NaOH
Molarity of NaOH__0.1182___M
Molarity of HCl__0.0009763__M
Volume HCl in Beaker ____10.00___mL
Initial Buret Volume ___0.02____ mL
Final Buret Volume __11.80___ mL
Volume of Base Delivered _11.82___mL
Total Number of Drops Delivered (from Pasco table) ____201____ drops
Correction Factor for x-axis ___0.586____ mL/drop
Use this correction factor in plotting the Excel plot of pH vs. volume (mL). Attach this
graph to your write up.
Page 1 of 9

Penn State Brandywine
Lab #4 Ionization Constant
Part 1. Acidity Constants for Phosphoric Acid
Molarity of NaOH _0.1182__M Volume of Acid in Beaker __10.00___mL
Initial Buret Volume __0.01 + 22.3 = 22.31 (refill)+ 0.01+ 8.60_____mL
Final Buret Volume __30.92________ mL
Volume of Base Delivered __30.92____mL
Total Number of Drops Delivered (from Pasco table) ___538___ drops
Correction Factor for x-axis ____0.0575____ mL/drop
Use this correction factor in plotting the Excel plot of pH vs. volume (mL). Attach this
graph to your write up.
Page 2 of 9

Penn State Brandywine
Lab #4 Ionization Constant
Use the graph to obtain the following information
Volume of base added at first neutralization point = 5 mL
pH at half first neutralization point = 1.98
pK
a1
= 1.98
Volume of base added at second neutralization point = 15 mL
pH at half second neutralization point = 6.86
pK
a2
= 6.86
Volume of base added at third neutralization point