CHT CHT Physics & Gas Laws in Hyperbaric Medicine 2

Question 1

Which gas law best explains why middle ear barotrauma occurs during hyperbaric chamber pressurization?

Accepted Answer

Boyle's Law

Answer

Boyle's Law explains that trapped gas in the middle ear decreases in volume as pressure increases, creating a pressure differential that causes barotrauma if not equalized.

Question 2

The 'oxygen window' in hyperbaric therapy refers to:

Accepted Answer

The partial pressure gradient that facilitates inert gas (nitrogen) elimination from tissues

Answer

The oxygen window is the pressure differential created when tissues consume oxygen, replacing it with a gas-free space that accelerates nitrogen elimination without bubble formation.

Question 3

Graham's Law of Diffusion states that lighter gases (lower molecular weight) diffuse:

Accepted Answer

Faster than heavier gases

Answer

Graham's Law states diffusion rate is inversely proportional to the square root of molecular weight, so lighter gases like helium diffuse faster than heavier gases like nitrogen.

Question 4

At 3 ATA breathing air (21% O2, 79% N2), the partial pressure of nitrogen is approximately:

Accepted Answer

1800 mmHg

Answer

At 3 ATA, total pressure = 3 × 760 = 2280 mmHg; nitrogen partial pressure = 0.79 × 2280 ≈ 1800 mmHg.

Question 5

Charles's Law describes the relationship between gas volume and:

Accepted Answer

Temperature at constant pressure

Answer

Charles's Law states that at constant pressure, the volume of a gas is directly proportional to its absolute temperature.

(CHT) Certified Hyperbaric Technician Practice Test

(CHT) Certified Hyperbaric Technician Practice Test

CHT CHT Physics & Gas Laws in Hyperbaric Medicine 2