Question

The density of methane is maximum under which conditions?

• A. \(0^\circ C,\ 2\ \text{bar}\)
• B. \(273^\circ C,\ 1\ \text{bar}\)
• C. \(273^\circ C,\ 2\ \text{bar}\)
• D. \(0^\circ C,\ 3\ \text{bar}\)

Hint:

For an ideal gas, \[ d=\frac{PM}{RT} \] Density is directly proportional to pressure and inversely proportional to temperature.

Answer 1

The Correct Option is D

Step 1: Express density proportionality.
From PV=nRT and d=m/V, we get d = PM/RT → d ∝ P/T. Maximum density needs highest P and lowest T.

Step 2: Compare given conditions.
0°C (273 K) is coldest; 3 bar is highest pressure. So 0°C, 3 bar maximizes P/T.

Step 3: Final Answer:
0°C, 3 bar (option 4).