7. (a) Explain the following phenomena with the help of Henry’s law. (i) Painful condition known as bends. (ii) Feeling of weakness and discomfort in breathing at high altitude.
Solution (a) (i) Henry's law represents a relation between solubility of gases in liquid and pressure.Scuba drivers when comes towards surface, the pressure gradually decreases. This reduce pressure releases the dissolve gas present in blood and leads to formation of bubbles of nitrogen in the blood. This creates a painful condition by blocking capillaries known as blends. (ii) At high attitude almospheric pressure is low as compared to surface which causes difficulty in breathing. On that condition we feel weakness and discomfort. (b) Soda water bottle kept at room temperature fizzes on opening due to different pressure inside and outside the bottle. When the bottle is opened to air, the partial pressure of CO2 above the solution decreases. As a result, solubility decreases and hence CO2 bubbles out.
