Question

Identify the use of mixture of Ar and $\text{N}_2$ from following.

• A. For magnetic resonance imaging
• B. For production of lasers
• C. To fill in electric bulbs
• D. To produce low temperature for research work

Hint:

While pure Argon can be used alone, adding a portion of Nitrogen gas is a clever engineering choice because it suppresses high-voltage electrical arcing across the filament leads much more effectively than pure noble gases!

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks us to identify the practical industrial application for a gas mixture containing Argon (Ar) and Nitrogen ($\text{N}_2$).

Step 2: Key Formula or Approach:
Argon is a chemically inert noble gas, and diatomic nitrogen gas is similarly unreactive under standard conditions due to its exceptionally strong triple bond ($\text{N}\equiv\text{N}$). These properties make their mixture excellent for providing non-reactive environments where thermal degradation or chemical oxidation must be avoided.

Step 3: Detailed Explanation:
Let us analyze why this specific combination is used in traditional incandescent light bulbs:
Inside an electric bulb, a tungsten filament gets heated to very high temperatures to emit light.
If oxygen or moisture were present, the hot filament would instantly oxidize and burn out.
Filling the bulb with an inert gas mixture of Argon and Nitrogen prevents oxidation.
Furthermore, the presence of these gas molecules introduces gas pressure that significantly reduces the evaporation rate of the hot tungsten atoms, greatly extending the functional lifespan of the bulb. Thus, option (C) is the correct application.

Step 4: Final Answer:
The mixture of Ar and $\text{N}_2$ is used to fill in electric bulbs, corresponding to option (C).