Question

question 17 of 30
what is the phase of water at 0.25 atm and 0°c?
phase diagram: pressure (atm) on y - axis (0, 0.25, 0.5, 1), temperature (°c) on x - axis (-10, 0, 0.01, 100); regions: ice (solid), water (liquid), water vapor (gas)
a. solid and gas
b. gas
c. solid and liquid
d. solid

Explanation:

Step1: Locate the point on the phase diagram

We need to find the point corresponding to \(0.25\) atm (pressure) and \(0^\circ\text{C}\) (temperature) on the given phase diagram of water.

Step2: Identify the region

Looking at the phase diagram, the region with pressure \(0.25\) atm and temperature \(0^\circ\text{C}\) is within the "Ice (solid)" region. The phase boundaries: at \(0^\circ\text{C}\) and \(1\) atm, water is at the solid - liquid - gas triple point? No, here at \(0.25\) atm and \(0^\circ\text{C}\), from the diagram, the area with these coordinates is in the solid (ice) region. The other options: Option A (solid and gas) would be near the solid - gas boundary, Option B (gas) is in the yellow region, Option C (solid and liquid) would be near the solid - liquid boundary (which is at higher pressure, around 1 atm at \(0^\circ\text{C}\) for normal ice - water, but here at \(0.25\) atm, it's solid). So the phase is solid.

Answer:

D. Solid