posted by Chuck on .
Why does it take longer to cook an egg until it is hard boiled in Denver (altitude 1 mile above sea level) than it does in NYC (near sea level)?
I answered this twice yesterday. The definition of boiling point of a liquid is the termperature of that liquid at which the vapor pressure of the liquid equals atmospheric pressure. The atmospheric pressure at sea level (NYC?) is 760 mm Hg while that at mile high Denver is less. That means water boils at a lower temperature in Denver than it does in NYC. For example, the boiling point of water may be 95 degrees C or some other value depending upon the atmospheric presure in Denver but we know it will be less than 100. And it will be even less than that on some of those tall mountains (15,000 feet or more) around Denver. So while the NYC egg is cooked at 100, the Denver egg is cooked at a temperature less than 100. So which will take longer?