Phases of Water Paul Doherty 0 006 bar

Phases of Water Paul Doherty

0. 006 _ bar triple point

Gas Water vapor is invisible

Water Gas ? Liquid drops are visible.

Water vapor bubbles in a liquid are visible.

0. 006_ bar At the triple point Solid, Liquid and gas exist together in equilibrium. At the critical point gas and liquid become indistinguishable.

Sweat droplets on skin: evaporation, (not eqilibrium. )

The vapor pressure above water is higher than above ice.

Water Boiler Reduce the presure on water and it will boil at room temperature.

Bubbles Pin = Pout + 4 T/r Pressure in a bubble increases as radius decreases. Where T is the surface tension in N/m

Surface tension is a result of the attractive forcs between molecules.

Water Freeze water by lowering the external pressure causing boiling and temperature reduction. Boiling is a cooling process.

Geyser The temperature of the water increases slowly. The pressure can change at the speed of sound. Creating an eruption.

Liquid water in contact with solid water

Ice is a mineral, water is molten ice.

Liquid Water Soid Water, ice less dense.

Density of Water Vs Temperature and Pressure At 1 bar Ice floats on water

To see an iceberg Float an ice balloon

Ice hexagonal crystal

Electric dipole moment of water. red blue +

Walking among large antarctic ice crystals

Large antarctic ice crystal

Ice takes on the structure of liquid water, near the surface at temperatures near 0 °C, this makes ice slippery.

Supercooled rain crystallizes when it hits a surface. Without a nucleation site the homogenious nucleation temperature is -42 C Frezing is a warming process, freezing water releases heat.

Watch Water Freeze In this exhibit water is cooled below freezing and remains a liquid until a “seed” causes ice crystal nucleation. Then the entire liquid crystallizes.

A 20 cm diameter snowflake. Supercooled water nucleated freezing into a hexagonal crystal.

Water made from lighter isotopes evaporates more rapidly.

Here, water is Solid Liquid and Gas in contact but NOT in equilibrium Yellowstone Norris Geyser Basin

Mars atmosphere has places at the triple point of water Here water ice has crystallized as snow on Mars. Image from the Viking Lander.

Mars Phoenix Lander Water Ice

Water Ice on Tempel 1 at -100 C vaor pressure is 0. 0014 Pa at 20 C it is 2300 Pa

Ice at -1 C hardness 1. 5 Mohs scale hardness 4 at -44 C hardness 6 at -80 C ice carved granite in antarctica.

It’s more complicated than that. MOre of the phase diagram of water.

On Europa Ice 3 may form. It is denser than liquid water. A water ocean on Europa may be sandwiched between ice 1 h on the top and ice 3 on the bottom.

Pluto Ice geology

Pluto water ice in blue

Enceladus

Enceladus Geysers

Titan Rivers

Titan Hydrocarbon Lakes

Titan Surface Water Ice Boulders

Mars Salty water Streaks

Mars Seasonal Water Flow

Superheated water