ARCH-C-11: Molten vs. Aqueous Electrolysis Discharge Competition & Electron Mole Stoichiometry

Compare molten vs. concentrated aqueous $\text{NaCl}$: in **molten $\text{NaCl(l)}$**, the only ions present are $\text{Na}^+$ and $\text{Cl}^-$, so **sodium metal ($\text{Na}$) forms at the cathode and chlorine gas ($\text{Cl}_2$) forms at the anode. In concentrated aqueous $\text{NaCl(aq)}$**, water provides $\text{H}^+$ and $\text{OH}^-$ ions: at the cathode, since sodium is more reactive than hydrogen, **hydrogen gas ($\text{H}_2$)** is discharged instead of $\text{Na}$; at the anode, because the halide ($\text{Cl}^-$) is concentrated, **chlorine gas ($\text{Cl}_2$)** is discharged (~110s).