Scuba divers experience chemical equilibrium in their bodies when they dive. Chemical equilibrium is achieved when the forward and reverse reactions occur at a constant rate. Le Chatelier’s principle states that when a system at equilibrium is disturbed (change in temperature, pressure or concentration) the equilibrium position shifts to counteract the disturbance. Scuba divers have implemented Le Chatelier’s principle to restore equilibrium when there is a change in pressure. We inhale air which is comprised of approximately 20% oxygen and approximately 80% nitrogen along with other gases. At normal atmospheric pressure our body breaks down oxygen and nitrogen. The body absorbs oxygen and small amounts of nitrogen, however, nitrogen cannot be completely dissolved at normal pressure. The body’s ability to intake gases changes when the pressure changes. My equilibrium equation of respiration under pressure:
O2 (g) + N2 (g) ⇋ 2NO (g)
This is similar to the actual equilibrium equation. It states that oxygen and nitrogen when inhaled dissolve into the body as nitrogen monoxide when the pressure is increased. Nitrogen monoxide decomposes to form oxygen and nitrogen when the pressure is decreased. In the ocean, the pressure is greater at the bottom of the ocean compared to the top. When scuba divers dive, they maintain a constant rate when ascending and descending to allow the body to remain at equilibrium. If the scuba divers ascend or descend rapidly the body will not have enough time to completely dissolve or remove nitrogen from the tissue to achieve equilibrium.
Figure 1.0: Inflamation of the joints due to accumulation of excess gas from rapid shange in pressure.
When the system is under pressure it shifts the equilibrium to reduce pressure. In this scenario there would be a greater absorption of nitrogen in the body. Le Chatelier’s principle is clearly demonstrated by scuba divers on a regular basis as their bodies accommodate to the pressure and reach chemical equilibrium with the inhaled gases. If the body is not properly brought to equilibrium, nitrogen bubbles start to form in the skin, blood vessels, joints and the brain which cause great pain and discomfort.
Figure 1.1: Decompression chamber (restoring body equilibrium by changing pressure gradually outside of the water)
Using Le Chatelier’s principle, the death rate of scuba divers decreased over the years as the divers’ bodies were better able to reach equilibrium with the surroundings. Now, divers are one of the true examples who inherit the concepts of Le Chatelier’s principle in their daily work.
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