Final answer:
The danger level of storing tanks of nitrogen versus carbon dioxide depends on storage conditions; however, carbon dioxide may present a higher immediate risk due to its toxic and asphyxiating properties, especially under high pressure and temperatures.
Step-by-step explanation:
Whether a closet where tanks of nitrogen are stored is more dangerous than one where tanks of carbon dioxide are stored depends on the storage conditions, which is choice (d). Both gases are inert and non-flammable, but they can pose a risk in large quantities due to the potential for asphyxiation if they displace oxygen in a confined space.
However, carbon dioxide is also an asphyxiant and at high concentrations is toxic, posing a greater immediate risk to human health compared to nitrogen, which is generally considered less toxic. Therefore, without proper ventilation and monitoring, a closet with carbon dioxide tanks may present a higher immediate risk.
Additionally, carbon dioxide is stored under high pressure and can present a risk of explosion in the case of a container failure, especially at high temperatures where the critical temperature can turn CO2 into a gas, increasing pressure.