Chemistry of Scuba-diving, Matthew Smith, Chemistry Honors

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. 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.