Chemistry Forum

Let’s say you’re stranded on Mars and the only food available to grow is potatoes. You realize that potatoes, being a tuber, are nitrogen-fixing and cannot grow without nitrogen. You have plenty of nitrogen, but it is not in a form that the plants can utilize, it is in its nitrate form. So you construct a reaction system to convert the nitrate ions to nitrogen – this system utilizes hydrogen ions, which you have carefully extracted by performing electrolysis on condensed water, and carbon monoxide, which you have tediously extracted from the atmosphere through fractional ozonation. The products are the desired nitrogen, water (bonus!), and the undesirable carbon dioxide (which we’ll vent back to the atmosphere). What volume of nitrogen gas and carbon dioxide gas would be produced at 17°C and 1.25 atm if the denitrification process of 200.0g of nitrate ions went to completion? Determine the partial pressures of both gas products as well since we don’t want to blow ourselves up.

Is it 30.72 L for both as well as .50 Partial Pressure for both? It seems like I am missing something or it is kind of a trick question.

Hi. It's a very interesting problem. What you have here is a redox reaction.
The nitrate ion gains electrons and turns into Nitrogen and CO turns into CO₂.
To know how much volume these gases will occupy you first have to do the balanced equation and then use P.V=n.R.T
To know the partial pressures you have to calculate the mole fraction of CO₂ and N₂ and then multiply them by the total pressure.
The volume of CO₂ is 126L and its partial pressure is 1atm
The volume of N₂ is 25L and its partial pressure is 0.25atm
The balanced equation is 5CO + 2H(+) + 2NO₃(-) = N₂ + 5CO₂ + H₂O[/img]