To avote berts, as well as, the toxle effeets of hish conceritrationss of nitrogen in the blood. the tanks used by scuba divers are filled wrth air diluted with fhellum i $1.20\%$ hellum. 5 fi. $296-\mathrm{ntregen}\mathrm{an}$ $32.196$ oxysen.

1. - At high altitudes the partial pressure of oxygen is less than that at the ground level. This leads to low concentrations of oxygen in the blood and tissues of people living at high altitudes or climbers. Low blood oxygen causes climbers to become weak and unable to think clearly. symptoms of a condition known as anoxia.
2. WOect of Temperature
3. Solubility of gases in liquids decreases with rise in temperature. When dissolved, the gas molecules are present in liquid phase and the process of dissolution can be considered similar to condensation and heat is evolved in this process. We have learnt in the last Section that dissolution process involves dynamic equilibrium and thus must follow Le Chatelier's Principle. As dissolution is an exothermic process, the solubility should decrease with increase of temperature.
4. Intextb Questions thity of ${\mathrm{H}}_2\mathrm{S}$ in water at $\mathrm{STP}$ is $0.195\mathrm{m}$, is used for the qualitative analysis. If W constant for