Question

As you dive down to check out a reef, the water exerts a pressure of 3 atm (2280 mm Hg), meaning that air is flowing out of the regulator at 3 atm. (3points) Given this,  

a) What is the fractional concentration of nitrogen?  

b) What is the partial pressure of nitrogen?  

c) Assuming that your dive was instantaneous how has the rate of diffusion of nitrogen into your blood changed (both quantitatively and qualitatively)?  

Please show work! :)

Answer 1

The nitrogen already present in the body from the surface and the nitrogen in the tank air are compressed by the increasing water pressure as the diver descends. The increasing pressure forces the nitrogen molecules close together to the point that they occupy less space. The diver's body fills the space left by the compression nitrogen by absorbing more nitrogen (also compressed) from the tank air. During this process the rate of diffusion of nitrogen is higher. The diver's body continues absorbing nitrogen until it is totally saturated. Once saturated there is negligible diffusion.