Which of these gases are outgassed from our volcanic eruptions?

a. water vapor, methane, carbon dioxide

b. carbon dioxide, water vapor, oxygen

c. ammonia, water vapor, oxygen

d. oxygen, methane, ammonia

e. helium, carbon dioxide, methane?

Answer is: a. water vapor, methane, carbon dioxide.

Beside this gases, sulfur dioxide (SO₂) is very common volcanic gas.

Minor gases are hydrogen (H₂), hydrogen sulfide (H₂S), hydrogen chloride (HCl), carbon monoxide (CO), and sulfur gas (S₂).

The easiest way to collect a sample of volcanic gases is by hand, placing a container directly in the gases.