Question

Which of the following options best describes why helium and argon are better options as known gases than air?

O The cylinder of air is more difficult to use, so its best to avoid using it.
O Air effuses too quickly, making it difficult to take data.
O Air effuses too slowly and would make the experiment take too long.
O The air provided does not have a well defined molecular weight.

Answer 1

Helium and argon are preferred over air due to their low density, inertness, and defined molecular weights, making them useful for applications where these characteristics are advantageous, such as in balloons, welding, and diving.

Step-by-step explanation:

Helium and argon are better options as inert gases than air for a number of reasons. First, helium is much less dense than air due to its low molar mass of 4.00 g/mol, allowing helium-filled balloons to float. Although helium effuses more quickly through the microscopic pores of a balloon than air, necessitating the use of materials like Mylar for better retention, it is safer to use than hydrogen and does not contribute to nitrogen narcosis when used in diving mixtures. Argon, also an inert gas with a higher molar mass, is useful for providing a non-reactive atmosphere in welding and light bulbs because of its low reactivity.

Helium is also used in applications where non-flammability is critical, while argon is chosen for its unreactivity. Both offer a more defined molecular weight compared to air, which is a mixture of various gases, each with its own molecular weight, making helium and argon more predictable in their behavior when used in scientific and industrial applications.