Final answer:
In an electrochemical cell, the anode is where oxidation happens, and the cathode is where reduction occurs. The given reaction N2(g) + H2(g) → NH3(g) is not typically an electrochemical reaction but rather a description of ammonia synthesis via the Haber process.
Step-by-step explanation:
The question relates to an electrochemical reaction in which nitrogen and hydrogen gases react to form ammonia. Specifically, the student is asked about redox reactions and the role of the cathode and anode in this process.
In an electrochemical cell, oxidation and reduction reactions occur at two separate electrodes. Oxidation reactions, where a substance loses electrons, occur at the anode. Conversely, reduction reactions, where a substance gains electrons, occur at the cathode. As seen in the example of tin being oxidized to Sn2+ at the anode, and nitrogen from the nitrate being reduced to nitric oxide at the cathode, the flow of electrons from the anode to cathode drives the electrical current in the cell.
In the case of hydrogen, the balanced reduction half-reaction shows that it is reduced, gaining electrons to form hydrogen gas. The electrode at which this occurs would be the cathode.
Here, it appears there is a misconception as nitrogen (N2) and hydrogen (H2) do not follow the reaction N2(g) + H2(g) → NH3(g) in an electrochemical cell setup. Ammonia synthesis traditionally involves nitrogen and hydrogen reacting under high pressure and temperature in the presence of a catalyst, not through electrochemical means.