Chapter 10- solids and liquids

crystalline solids

long range, repeating 3-dimensional pattern of how particles are arranged and relative to the next

solids

rigid, ordered arrangement, fixed volume, not compressible (particles very close together)

liquids

particles are able to slide past each other, fixed volume but variable shape, very slightly compressible, short range order

gas

fluid, least dense form of matter, shape and volume are variable, highly compressible, constant, random, chaotic motion

solid→liquid

• melting (fusion)

• endothermic

liquid→solid

• freezing

• exothermic

liquid→gas

vaporization

endothermic

gas→liquid

condensation

exothermic

solid→gas

• sublimation

• endothermic

gas→solid

deposition

exothermic

ΔHfus

conversion between solid < — > liquid

ΔHvap

conversion between gas < — > liquid

ΔHsub

conversion between solid < — > gas

increasing order of E of ΔHsub, ΔHvap, and ΔHfus

ΔHfus < ΔHvap < ΔHsub

ΔHsub = …..?

ΔHsub= ΔHfus + ΔHvap

what equation do you use when head is added/removed and the phase does NOT change but temp. does

q=msΔT

what equation do you use when head is added/removed and temp remains constant but phase changes

q=(mol substance)(ΔH phase change)

what do heating and cooling curves show

how temp changes over time compared to how much energy is added at constant pressure

what does a phase diagram show

shows the relationship between phase, time, and pressure

dynamic equilibrium exists between 2 phases:

1) rate of forward change= rate of reverse change

2) populations of both phases are constant with time

what is a super heated liquid

you heat the liquid so fast, the substance doesn’t have enough time to catch up and absorb heat to convert phases

what is a supercooled liquid

you cool the liquid so fast, the substance doesn’t have enough time to catch up when losing heat to convert phases