Which of the following is a standard conversion for a voltage of 100 mV SCE to CSE?

To convert a voltage measured in millivolts versus a standard calomel electrode (SCE) to a value in millivolts versus a saturated calomel electrode (CSE), it’s important to understand the difference in reference points between the two electrodes.

A saturated calomel electrode (SCE) typically has a half-cell potential of approximately 0.241 V (241 mV) versus the standard hydrogen electrode (SHE) at 25°C, whereas a CSE has its own specific potential. The conversion from SCE to CSE generally requires adding or subtracting a known factor based on the particular properties of the electrodes involved. In this case, the conversion factor used to adjust the reading from SCE to CSE is typically about -0.075 V, or -75 mV.

Thus, when you convert 100 mV measured against SCE to a CSE scale, you subtract this 75 mV factor. This works out to a final value of 25 mV when using the correct conversion. Therefore, the corresponding CSE value is found to be 25 mV when starting from the SCE voltage of 100 mV.

The correct choice aligns with this calculated conversion