chem- chapter 10- states of matter

solid → liquid

melting

liquid → gas

boiling

what do solids have to have

crystals

unit cell

repeating pattern

amorphic

without crystals (without shape)

what is it called when substances can hold their shape for a long period of time

metastable

what are metastable substances called

super cooled liquids

examples of super cooled liquids

glass, plastic, rubber and asphalt

hydrated

have water molecules attached to the crystals

anhydrous

without water

isomorphic

2 or more substances with the same crystal shape

polymorphic

one substance with 2 or more crystal shapes

example of polymorphic substance

carbon (diamonds, lead, coal, bucky balls)

anisomorphic and allotrophic

under different conditions you get different crystals (affected by moisture, temp and pressure)

hygroscopic

crytals are able to take water out of the air

kinetic energy

the energy of motion (measured with thermometer)

how does heat move

high to low

expansion

solids and gases expand but liquid don’t

fluidity

particles can roll around each other (gases and liquids)

low viscosity

pouring a cup of water

viscocity

resistance to flow

solids

particles vibrate around a fixed point (definite shape and volume)

liquids

particles vibrate around a moving point (definite volume but no definite shape)

gases

have the most energy (no definite shape or volume)

density depends on what

the space between particles

high viscosity

pouring syrup

low density

gases have low density

why does ice float

its less dense therefore the particles have more space between them

diffusion

random scattering of particles from high to low

what is surface tension

when the particles at the surface of a liquid “lock arms” and make a barrier

what is surface tension due to

it is due to unbalanced forces

what does high/low surface tension depend on

what type of bonds the molecules have, ex. water (dipole-dipole) very strong ST

vaporization

when a solid or liquid changes to a gas

what does vaporization depend on

what the substance is at room temp

if a substance is a solid or liquid at room temp it is a

vapor

if a substance is a gas at room temp it is a

gas

evaporation

when particles on top of a liquid “jump out”

what is the difference between evaporation and vaporization

in evaporation the particles “leaving” are at the surface while in vaporization they are further down and need more energy to pop out

volatile

evaporates at room temp

examples of volatile liquid

alchohol and water

deliquescent

crystals can take so much water out of the air that they liquify

desiccant

“dry agents” can take “tons” of water out of the air and not get wet

efflorescent

crystals release water into the air

phase

physical state (L,S, or G)

phase change

going from one state to another

gas → liquid

condensation

liquid → solid

freezing

vapor pressure

when the particles that have vaporized hit the walls of your container with a certain amt of force

dynamic equillibrium

for every particle that escapes your container, one gets pushed back down, no net change

boiling point

when the VP of liquid equals the VP of the gas

melting point

when the VP of solid equals the VP of the L

what is waters boiling point

100 degrees C

what is waters melting point

0 degrees C

specific heat capacity

the amount of energy needed to raise 1g or a substance at 1 degree C (g/C)

why does the temp stay the same during phase changes

the particles are changing position which is potential energy and potential energy isn’t measured by temp

sublimation

when a substance goes from a solid to gas and skips the liquid stage

what is a triple pt in a phase diagram

the point where you could have a solid, liquid, or gas at the same time

phase diagram

compare temp and pressure and tells you at what temp and pressure your substance is a solid, liquid or gas

as pressure goes up, what goes down

sea level

do melting and freezing occur at the same rate

yes

during melting is energy gained or lost

gained

during freezing is energy gained or lost

lost

heat of vaporization

the amt of energy needed to boil one mole of liquid

heat of fusion

the amt of energy needed to melt one mole of a solid

critical temp

the temp above which the substance cannot exist in liquid state

critical pressure

the lowest pressure at which the substance can exist as a liquid at the critical temp

crystal lattice/space lattice

the 3D arrangement of particles in crystals

what is moth balls and dry ice an example of

sublimation