Question

An aqueous ammonium nitrate battery might be designed as NH4ClaqjjN aNO3;aq.

(a) What is the reactant at the anode? (Hint: RED CAT)

(b) At 25 oC in water, the saturation concentration of NH4Cl is 391.8 g/L and of N aNO3 is 91.2 g/100 mL. If the battery shown above is formed with the saturation concentrations in the 0.1000 liter volume of each half of the cell and the battery does not explode, what is the potential of the battery before it is discharged, based on the reaction of ammonium and nitrate to form nitrous oxide? Take the initial concentration of N2O as 1.0 mmol/liter.

(c) A battery formed at saturation is discharged at 25 oC with 100 % efficiency to form only N2O and water. How much energy is released? (d) What are the final concentrations of ammonium and nitrate? (Hint: Consider a balance sheet.) How many moles of N2O are produced? Should the cathode, the anode, or both be open compartments and why?

(e) Is the ammonium nitrate battery a good idea? Under what conditions might it be useful? Comment in 3 or fewer sentences.

Answer 1

In an electrochemical cell, reduction occurs at cathode where cations are reduced by accepting electrons coming from anode through external circuit. Oxidation takes place at anode. Therefore any metal having large negative standard reduction electrode potential can be used as anode.