Question

Sauba divers when come towards the surface, pressure gradually decreases

resulting in release of dissolved gases leading to formation of bubbles of N2

gas in

the blood which block the capillaries and thus bends are created. To avoid bends

and toxic effect of high concentration of N2

gas, the air is diluted with helium.

After the above passage, answer the following :

(a) Why is the harmful condition of bends overcome by the use of helium ?

(b) Which law is used to calculate the concentration of gases in solution ? (c) Mention the value associated with providing divers air diluted with helum.

(d) Which gas has less value of KH , O2

or He, and why ?

Answer 1

a) He is highly unreacrive and has a high viscosity with which it can flow upwards with certain pressure decreasing bends
b) Henry's law is used to calc conc of gas in solution
c) 80% of He with 20% O2 is used
d)O2, cuz it is more soluble in water