Question

$He$ is added to oxygen supply used by deep sea divers because:

• A. It is less soluble in blood than nitrogen at high pressure.
• B. it is lighter than nitrogen.
• C. It is readily miscible in oxygen.
• D. It is less poisonous than nitrogen.

Answer 1

Answer: (A)

It is less soluble in blood than nitrogen at high pressure.

The main reason for adding helium to the breathing mix is to reduce the proportions of nitrogen and oxygen below those of air, to allow the gas mix to be breathed safely on deep dives.