The glass electrode used in commercial pH meters gives an electrical response proportional to the concentration of hydrogen ion. Converting these responses to a pH reading requires calibration of the electrode against standard solutions of known H+ concentration. Preparation of the pH 7.00 standard buffer uses sodium dihydrogen phosphate (NaH₂PO · H₂O, FW 138) and disodium hydrogen phosphate (Na₂HPO4, FW 142). Phosphoric acid (H₂PO4), a triprotic acid, has three pK₁ values: 2.14, 6.86, and 12.4. Calculate the weight in grams of sodium dihydrogen phosphate and disodium hydrogen phosphate needed to prepare 1.25 L of standard buffer with a total phosphate concentration of 0.09 M. NaH₂PO4 = g Na₂HPO4 = g

The glass electrode used in commercial pH meters gives an electrical response proportional to the concentration of hydrogen ion. Converting these responses to a pH reading requires calibration of the electrode against standard solutions of known H+ concentration. Preparation of the pH 7.00 standard buffer uses sodium dihydrogen phosphate (NaH₂PO · H₂O, FW 138) and disodium hydrogen phosphate (Na₂HPO4, FW 142). Phosphoric acid (H₂PO4), a triprotic acid, has three pK₁ values: 2.14, 6.86, and 12.4. Calculate the weight in grams of sodium dihydrogen phosphate and disodium hydrogen phosphate needed to prepare 1.25 L of standard buffer with a total phosphate concentration of 0.09 M. NaH₂PO4 = g Na₂HPO4 = g

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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