An electrolytic cell is set up containing a 1 : 1 molar mixture of molten NaCl(l) and…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
An electrolytic cell is set up containing a 1 : 1 molar mixture of molten NaCl(l) and CaCl₂(l) maintained at 800 °C. Graphite serves as the inert anode, and an iron cathode is connected to an external power supply that delivers a constant current of 5.00 A for 1.07 h. During electrolysis a shiny silver-gray metal coats the cathode, and yellow-green gas bubbles are observed at the anode.
Faraday constant: F=96500C mol−1
(a) Identify the chemical species reduced at the cathode and the species oxidized at the anode based on the macroscopic observations.
(b) Write the balanced half-reactions occurring at the cathode and anode, then combine them to give the overall reaction taking place in the cell.
(c) Calculate the mass of metal deposited on the cathode during the 1.07 h of operation.
(d) If the average potential maintained by the power supply is 4.7 V, determine the minimum amount of electrical energy (in kJ) delivered to the cell during electrolysis.