A student wishes to determine the standard reduction potential of an unknown metal electrode in a half-cell. They set up an electrochemical cell using a known standard hydrogen electrode (SHE) as the reference electrode and the unknown metal electrode as the working electrode. A voltmeter is used to measure the potential difference between the two electrodes. The reading is +0.45 V. What is the standard reduction potential of the unknown metal electrode in volts?

Question

A student wishes to determine the standard reduction potential of an unknown metal electrode in a half-cell. They set up an electrochemical cell using a known standard hydrogen electrode (SHE) as the reference electrode and the unknown metal electrode as the working electrode. A voltmeter is used to measure the potential difference between the two electrodes. The reading is

Answer 1

To determine the standard reduction potential of the unknown metal electrode, we can use the Nernst equation for the cell potential. In this case, since we are dealing with standard conditions, the Nernst equation simplifies to:E_cell = E_unknown - E_SHEWhere E_cell is the measured cell potential, E_unknown is the standard reduction potential of the unknown metal electrode, and E_SHE is the standard reduction potential of the standard hydrogen electrode.The standard hydrogen electrode  SHE  has a standard reduction potential of 0 V by definition. The measured cell potential  E_cell  is given as +0.45 V. Plugging these values into the equation, we get:0.45 V = E_unknown - 0 VE_unknown = 0.45 VSo, the standard reduction potential of the unknown metal electrode is +0.45 V.