Question

Using the phase diagram for `H_2O`, what phase is water in at 1 atm pressure and -5 C?

Answer 1

Clearly water is a solid phase under these circumstances.

Explanation:

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The phase diagram plots pressure (in `"mm Hg"`) against temperature. While the graph is non-linear, the normal boiling point, and the normal freezing point are clearly depicted when `P="1 atm"="760 mm Hg"`. The negative slope of `(DeltaP)/(DeltaT)`, which illustrates that ice FLOATS, is highly unusual.