15-22. List the sources of error associated with pH measurement with the glass electrode.

An ion-selective electrode (ISE) produces voltage output (mV) proportional to solution pH. You have three standard pH solutions (4, 7, and 10). Assuming that pH 7 buffer solution is used together with pH 4 for calibration prior to measuring acidic solutions and together with pH 10 before measuring alkaline solutions, produce a flowchart of the calibration routine for a single pH ISE.

When the difference in pH across the membrane of a glass electrode at 25C is 4.63 pH units, how much voltage is generated by the pH gradient? Assume that the constant in Equation 15-6 is 1.00.

Please show a clear picture of the spreadsheet /excel file of the data including the equations used in excel.

Please answer ASAP

A glass electrode with a SCE reference electrode is calibrated at 25 °C with a pH 4.00 standard buffer; the voltage was 0.855 V. What would be the voltage (in V) measured for a 1.00 x 102 M solution of acetic acid (K₁-1.75 × 10-5)? Remember that at 25 °C, the term (2.303RT/F) equals 0.05916.

Calibration of a glass electrode gave a reading of 134.9 mV with a 0.05 m potassium hydrogen phthalate buffer standard ( pH = 4.015), and a reading of -69.1 mV with a 0.08 m HEPES, 0.08 m NaHEPES, 0.08 m NaCl buffer standard (pH = 7.454), both measured at 30 °C. What is the observed slope (mV/pH unit) of the calibration curve? slope observed slope theoretical What is the theoretical slope at 30 °C? pH -58.1 5.29 Incorrect What is the pH of an unknown that gives a reading of 41.4 mV with this electrode at 30 °C? Incorrect Incorrect mV/pH mV/pH

Calibration of a glass electrode gave a reading of 139.1 mV with a 0.05 m potassium dihydrogen citrate buffer standard ( pH = 3.766), and a reading of -75.5 mV with a 0.08 m HEPES, 0.08 m NaHEPES, 0.08 m NaCl buffer standard (pH = 7.454). both measured at 30 °C. What is the observed slope (mV/pH unit) of the calibration curve? slope observed= mV/pH What is the theoretical slope at 30 *C? slope theoretical What is B, the electromotive efficiency, to three significant figures? B= What is the pH of an unknown that gives a reading of 50.2 mV with this electrode at 30 "C? mV/pH

Calibration of a glass electrode gave a reading of 126.5 mV with a 0.05 m potassium hydrogen phthalate buffer standard ( pH = 4.015), and a reading of -73.7 mV with a 0.008695 m potassium dihydrogen phosphate, 0.0343 m disodium hydrogen phosphate buffer standard (pH = 7400), both measured at 30 C. What is the observed slope (mV/pH unit) of the calibration curve? slopeurd= -59.17 mV/pH What is the theoretical slope at 30 C? 0.984 mV/pH slopeeical= What is 8. the electromotive efficiency, to three significant figures?

Calibration data for a bromide ion-selective electrode (ISE) was collected and [Br¯] (M) Potential (mV) recorded in the table. The potential of the ISE was measured against a saturated 0.300 -21.2 calomel electrode (SCE). All solutions were buffered at a pH of 7.56. A linear calibration curve can be constructed from this data as a plot of potential (in mV) vs. 0.0300 36.5 log [Br]. Determine the slope and y-intercept of such a plot of the calibration 0.00300 96.6 data given. 0.000300 154.8 0.0000300 225.6 slope у-intercept Two unknown solutions were tested for [Br] using the same bromide ISE. The potential reading for unknown 1 was 1.9 mV, and the potential reading for unknown 2 was 183.4 mV. Using the calibration curve you constructed, determine the concentration of Br¯ in each unknown solution.