What is the specific gravity of hydrogen sulfide?

What is the specific gravity of hydrogen sulfide?

• A. 0.9
• B. 1.0
• C. 1.2
• D. 1.5

Answer: (C)

Specific gravity for gases compares a gas’s density to that of air. Hydrogen sulfide has a molar mass of about 34 g/mol, while air is about 29 g/mol, so H2S is denser than air. The ratio works out to roughly 34/29 ≈ 1.17, commonly rounded to 1.2. That places it above 1, meaning it’s heavier than air, which is why the typical value used is around 1.2. Values like 0.9 would imply it’s lighter than air, 1.0 would mean it’s about the same as air, and 1.5 would be far heavier than what is typical for H2S, making 1.2 the best fit.

Specific gravity for gases compares a gas’s density to that of air. Hydrogen sulfide has a molar mass of about 34 g/mol, while air is about 29 g/mol, so H2S is denser than air. The ratio works out to roughly 34/29 ≈ 1.17, commonly rounded to 1.2. That places it above 1, meaning it’s heavier than air, which is why the typical value used is around 1.2. Values like 0.9 would imply it’s lighter than air, 1.0 would mean it’s about the same as air, and 1.5 would be far heavier than what is typical for H2S, making 1.2 the best fit.