Prove that the freezing point of water is 0 and the boiling point of water is 100?

1 Answer
Jul 4, 2017

...Huh? 0 what?

The normal boiling point of water is 100.00C, and the normal freezing point of water is indisputably 0.00C. There is no need to discuss the so-called "vaporization point" because it's a synonym... (for what?)

The phase diagram here quite clearly proves it.

https://s3-us-west-2.amazonaws.com/https://s3-us-west-2.amazonaws.com/

The "normal" phase transition temperatures by definition are the temperatures at 1.00 atm where phase transitions will occur.

If you cross a phase coexistence curve (such as ¯¯¯¯¯¯AD or ¯¯¯¯¯¯AE), you transition to another phase. The easiest and most common way to do that is to heat or cool, i.e. move horizontally. Rightwards = heating up.

Hence, at 1.00 atm, the normal freezing/melting point is at 0.00C and the normal boiling/condensation point is at 100.00C, as indicated by the dotted lines and, well, the words on the image.

QED


So, can you "prove" that the critical point is at 373.99C and 217.75 atm? Can you convince yourself that the triple point is at 0.0060 atm and 0.01C?