GASCO Exit Exam • Set 2 Question 3 of 30

What is the density of Methane gas compared to air at standard ambient temperature (+20°C)?

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Direct Answer

Option B: Lighter than air (vapor density ~ 0.55 relative to air)

Methane gas at ambient temperature is lighter than air (~0.55 SG) and disperses upward quickly. Cold methane (-162°C) is initially heavier than air.

All Options

Heavier than air

Lighter than air (vapor density ~ 0.55 relative to air) (Correct Answer)

Heavier than lead

Same density as water

Detailed Explanation & Context

Methane gas at ambient temperature is lighter than air (~0.55 SG) and disperses upward quickly. Cold methane (-162°C) is initially heavier than air.

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Advanced Training for Liquefied Gas Tanker Cargo Operations (GASCO).

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