Final answer:
The boiling point of water decreases with a reduction in atmospheric pressure. At lower pressures, such as in high altitudes or a vacuum, water can boil at room temperature. This phenomenon occurs because the water's vapor pressure reaches atmospheric pressure at a lower temperature.
Step-by-step explanation:
The boiling point of water is influenced by the atmospheric pressure. At sea level where the atmospheric pressure is approximately 1 atm, water boils at 100°C. However, when the atmospheric pressure decreases, such as in a low-pressure system or at higher altitudes, the boiling point of water also decreases. For example, at 5000 feet above sea level, atmospheric pressure is lower, which means water will boil at a temperature lower than 100°C, making it take longer to cook food like eggs because the physical and chemical changes occur more slowly.
When a liquid reaches a temperature at which its vapor pressure is equal to the external pressure, it begins to boil. This can occur at a lower temperature if the external pressure is less than 1 atm, as is the case in a vacuum chamber. Thus, under sufficiently low pressure conditions, water can boil at room temperature. This demonstrates that boiling point and vapor pressure are inversely related to atmospheric pressure.