A presentation to explain the Chemistry behind scuba-diving. Made by Matthew Smith.

1. Matthew Smith
Chemistry Honors

2. Brief Information
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• Scuba-diving is an underwater hobby.
•To scuba-dive, one must become certified
through classes and hands-on-training through
the organization PADI (Professional Association
of Diving Instructors).
•Major equipment of a scuba-diver’s gear is their
regulator, tank, and BCD. The regulator and
tank are used for breathing and the BCD
controls buoyancy.
•The NUMBER ONE rule of scuba-diving is DO
NOT hold your breath.

3. Chemistry
 Boyle’s Law- is an inverse relationship of pressure and
volume. As volume decreases, pressure increases, or
inversely (Belleman 5). P1V1=P2V2
 When divers descend below sea level, they are adding
more pressure than normal atmospheric pressure. (1
atm)
 When we go to the bottom of a pool, we feel a lot of
pressure. How are we able to withstand depths up to 30
feet?

4. Boyle’s Law Continued
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•When scuba-diver’s dive, the tank that
supplies the oxygen, gives it at the same
pressure as the surrounding pressure
(Belleman 5.)
•As stated earlier, the most important rule of
scuba-diving is to not hold your breath.
Why?
•The pressure on us while diving causes
cavities in our body that contains air to be
compressed.
•If we hold our breath and expand our lungs
but do not breathe out, the pressure can
cause damage to our lungs and can burst
lung sacs (Belleman 5).

5. Ascending with Boyle’s Law
 When a diver ascends to the surface, the pressure is
decreased which causes the volume of gas in our cavities
to expand.
 That is why divers ascend in increments to lessen the risk
of over expanding the lungs (Wood 1).
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6. Henry’s Law/The Bends
•Henry’s Law- the solubility of gas is directly linked to pressure
(Belleman 6).
•This means that as a diver descends gases dissolve more easily into
our body than at normal atmospheric pressure.
•Nitrogen is a gas that is found in normal breathing air.
•When a diver descends, nitrogen dissolves into
our body more easily.
Lionfish

7. Decompression Sickness
 If divers ascend to fast, not only may strain occur to the
lungs due to Boyle’s Law, but nitrogen bubbles may
form which cause the “Bends” or Decompression Sickness
(Belleman 6).
 The “Bends” occurs when the pressure is released too fast
on ascension and the nitrogen gas bubbles escape (Wood
1).
 Decompression sickness can cause pain to the spinal cord
and the muscles (David, Kulkarni, Phatak 1). Also death
could occur.

8. Implications
Understanding the gas laws helps us
understand how to protect ourselves while
scuba-diving.
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pot.com
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Knowing how pressure
affects our bodies, we can
know how our scuba
equipment helps us dive
to large depths.

9. Works Cited
 Belleman, Mellisa, and Tim Graham. "Gas Laws and Scuba
Diving." ChemMatters Feb. 2001: 4+. ACS. Web. 13 Apr.
2014.
 David, Eric, Pravin Kulkarni, and Uday Phatak.
"Decompression syndrome (Caisson disease) in an Indian
diver." Annals of Indian Academy of Neurology 13.3 (2010):
202. General Science Collection. Web. 13 Apr. 2014.
 Wood, Mary. "Boyle's and Charles' laws: a load of hot air?"
Chemistry Review Sept. 2009: 8+. General OneFile. Web. 28
Apr. 2014.