Phase Diagrams

Question 1

What is a phase diagram?

Answer 1

Graphical way to show the pressures and temperature a at which a substance will exist at either a solid, liquid, or gas (or somewhere in between those phases)

Question 2

Y axis

Answer 2

pressure

Question 3

x axis

Answer 3

temperature

Question 4

lines of equilibrium

Answer 4

the dividing lines between each phase on the graph. They represent where two phases (at a certain temp & pressure) can occur at the same time

Question 5

critical point

Answer 5

beyond this point liquids and gases are indistinguishable

Question 6

triple point

Answer 6

the perfect temp and pressure that a substance will exist at equilibrium of all 3 phases

Question 7

What is unique about the phase diagram for water?

Answer 7

it has a negative solid-liquid line of equilibrium. (buttcrack line points up to top left corner)

Question 8

Water is unusual because it is ____ as a liquid than as a solid

Answer 8

denser. This is because when water is frozen, it has more space between the molecules. This means that when you take solid water and add pressure it turns into water (instead of a gas, like most compounds)

Question 9

water at low pressure exists as a?

Answer 9

gas

Question 10

When you add pressure to a gas or solid of water, they both become?

Answer 10

liquid

Question 11

Most compounds as a solid are ____ than as a liquid. This is not true for?

Answer 11

denser.

This is not true for water. Water is denser as a liquid (this is why ice floats)