Calibration of a glass electrode gave a reading of 145.9 mV with 0.05 m potassium dihydrogen citrate buffer standard (pH = 3.766) and a reading of -70.1 mV with 0.008695 potassium dihydrogen phosphate, 0.0343 m disodium hydrogen phosphate buffer standard (pH = 7.400), both measured at 30°C.
What is the theoretical slope at 30°C? What is ?, the electromotive efficiency to three significant figures?? ? What is the pH of an unknown that gives a reading of 46.7 mV with this electrode at 30°C?