honors chemistry states of matter

kinetic theory

all matter consists of tiny particles that are in constant motion

elastic collisions

A collision in which no kinetic energy is lost; gas particles have same speed before and after the collision

hydrogen bonding

strong type of intermolecular dipole-dipole attraction that occurs between hydrogen and F, O or N

london dispersion forces

the intermolecular attraction resulting from the uneven distribution of electrons and the creation of temporary dipoles

dipole-dipole forces

intermolecular forces that exist between polar molecules, the strength of intermolecular attractions increase when polarity increases

translational motion

movement in which an entire molecule moves in a definite direction (gas)

vibrational motion

periodic motion of atoms within a molecule (solids)

rotational motion

motion of a body that spins about an axis (liquids)

compressibility

a measure of how much the volume of matter decreases under pressure

difussion

movement from an area of higher concentration to an area of lower concentration

effusion

a process by which gas particles pass through a tiny opening

pressure

force per unit area

manometer

instrument that measures pressure

barometer

instrument that measures atmospheric pressure

temperature

a measure of how hot or cold something is

vacuum

a space where no particles of matter exist

phase diagram

a graph showing the conditions at which a substance exists as a solid, liquid, or vapor

triple point

the temperature and pressure conditions at which the solid, liquid, and gaseous phases of a substance coexist at equilibrium

position of particles in a liquid [are fixed/can vary]

can vary

total volume of a liquid is [fixed/variable]

fixed

why is the density of a liquid higher than that of a gas of the same substance?

because of the intermolecular forces that hold liquid particles together

liquids are considered to be [incompressible/compressible]

incompressible, because particles are already tightly packed

viscosity

a liquid's resistance to flow (thickness)

stronger intermolecular forces result in [higher/lower] viscosity

higher, due to strong bonds

bigger particle size and shape result in [higher/lower] viscosity

higher, because big particles move more slowly

higher temperature results in [higher/lower] viscosity

lower (indirect relationship), think oil spreads faster on a pan when it is heated, or cold maple syrup travels slower than warm

surface tension

the energy required to increase the surface area of a liquid by a given amount

why is water's surface tension so high?

because water has hydrogen bonds, which causes strong intermolecular forces

surfractant

any substance that interferes with the hydrogen bonding between water molecules and thereby reduces surface tension

cohesion

attraction between molecules of the same substance

adhesion

attraction between molecules of different substances

crystalline solid

a solid whose atoms, ions, or molecules are arranged in an orderly, geometric structure

lattice

regular arrangement of particles

unit cell

the smallest group of particles within a crystal that retains the geometric shape of the crystal

allotrope

an element with different forms with different molecular structures (ex. carbon)

ionic solid

solid composed of positive and negative ions held together by strong electrostatic attractions

- hard, brittle, high melting point, poor conductivity

ex. NaCl, KBr, CaCO3

molecular solid

a solid composed of neutral molecules at the lattice points

- soft, low to moderately high melting point, poor conductivity

ex. I2, H2O, NH3, CO2, C12H22O11

covalent network solid

a solid that consists of atoms held together in large networks or chains by covalent bonds

- very hard, very high melting point, often poor conductivity

ex. diamond and quartz

metallic solid

solid composed of metal atoms surrounded by mobile valence electrons

- soft to hard, low to high melting point, malleable or ductile, good conductivity

ex. all metallic elements

amorphous solid

a solid made up of particles that are not arranged in a regular pattern

ex. glass, rubber, plastics

5 differences between amorphous and crystalline solids

- amorphous solids lack a definite geometric shape

- unclean cleavage when cut

- isotropic (physical properties are the same in all directions)

- non-definite melting point

- non-definite heat of fusion

evaporation

- when vaporization occurs only at the surface of a liquid

- doesn't require liquid to be above boiling point

- can occur from collision of air particles

vaporization

- the change of state from a liquid to a gas

- occurs when liquid is above boiling point

dynamic equilibrium

when the rate of evaporation is equal to the rate of condensation

vapor pressure

the pressure exerted by a vapor over a liquid in dynamic equilibrium

volatility

the tendency of a substance to vaporize

substances with high vapor pressures are [more/less] volatile

more because there are less intermolecular forces

substances with low vapor pressures are [more/less] volatile

less because there are less intermolecular forces

IMFs and vapor pressure have a [direct/indirect] relationship

indirect, as IMFs increase, vapor pressure decreases

(because higher IMFs means higher boiling point)

boiling point and vapor pressure have a [direct/indirect] relationship

indirect, as boiling point increases, vapor pressure decreases (because less vapor pressure makes a substance difficult to boil)

temperature and vapor pressure have a [direct/indirect] relationship

indirect, related to boiling point. lower boiling point means lower IMFs, so vapor pressure increases and the substance is more volatile

normal boiling point

the boiling point of a liquid at a pressure of 1 atm

critical point

the temperature and pressure at which the gas and liquid states of a substance become identical and form one phase

volume (v) and gas pressure have a [direct/indirect] relationship

indirect, as one increases the other decreases

temperature (T) and gas pressure have a [direct/indirect] relationship

direct, as one increases so does the other

amount of gas (n) and gas pressure have a [direct/indirect] relationship

direct, as one increases so does the other

boyle's law

P1V1\=P2V2

T and n are constant

isothermal system

charles' law

V1/T1\=V2/T2

P and n are constant

isobaric system

gay-lussac's law

P1/T1\=P2/T2

V and n are constant

isochoric system

combined law

P1V1/T1\=P2V2/T2

n is constant

avogadro's law

V1/n1\=V2/n2

T and P are constant

isothermal and isobaric system

ideal gas law

PV\=nRT

using ideal gas law to determine molar mass

M \= mRT/PV

(m is in g)

using ideal gas law to determine density

p \= MP/RT

graham's law of effusion

rate A/rate B \= square root of Mb/Ma

dalton's law of partial pressures

states that the total pressure of a mixture of gases is equal to the sum of the pressures of all the gases in the mixture

Ptotal \= P1 + P2 + P3...