Final answer:
The atmospheric pressure on Mount Everest allows water to boil at 70°C due to lower vapor pressure at high altitudes. Pressure is around 253 mm Hg on the summit, which is significantly lower than at sea level, resulting in lower oxygen levels.
Step-by-step explanation:
The atmospheric pressure atop Mount Everest is typically much lower than at sea level. When water boils at 70.0°C on Mount Everest, it is because the atmospheric pressure is reduced such that the vapor pressure of water equals the atmospheric pressure at this lower temperature. The vapor pressure of water is known to be 68 kPa at about 90 °C based on vapor pressure charts. Since boiling occurs when vapor pressure equals atmospheric pressure, we can infer that on Mount Everest, the atmospheric pressure is roughly equal to the vapor pressure of water at 70°C, although the exact pressure at that boiling point would need to be referenced from a detailed vapor pressure chart or determined through experiment.
Furthermore, on the summit of Mt. Everest (elevation of 8848 m), the air pressure is noted to be around 253 mm Hg, which is significantly lower than the sea level pressure of 760 mm Hg. This drop in pressure with increased altitude is accompanied by a decrease in oxygen levels, necessitating that climbers bring supplemental oxygen to maintain normal physiological functions.