Why Does Pure Water Boil Below 100°C at High Altitudes?
Discover why pure water doesn't always boil at 100°C and how altitude affects boiling points through atmospheric pressure changes.
408 views
Pure water does not always boil at 100°C due to variations in atmospheric pressure. At higher altitudes, where air pressure is lower, water boils at a lower temperature. Conversely, at or below sea level, where atmospheric pressure is higher, water tends to boil at exactly 100°C. Adjustments in cooking times or pressures, such as using a pressure cooker, may be required based on your location's altitude to ensure accurate boiling points for recipes.
FAQs & Answers
- Why does water boil at a lower temperature at high altitudes? At high altitudes, atmospheric pressure is lower, which reduces the temperature at which water molecules can escape as vapor, causing water to boil at temperatures below 100°C.
- How does atmospheric pressure affect the boiling point of water? Higher atmospheric pressure increases the boiling point of water, while lower pressure decreases it, because boiling occurs when vapor pressure equals atmospheric pressure.
- Can pressure cookers change the boiling point of water? Yes, pressure cookers increase the pressure inside the cooking vessel, raising water's boiling point above 100°C to cook food faster.
- Do I need to adjust cooking times at high altitudes? Yes, because water boils at lower temperatures at higher altitudes, foods often require longer cooking times or pressure cooking to ensure proper preparation.