Chapter 10: Liquids and Solids

Intermolecular forces:

attractive forces between neighboring molecules

Gases have no apparent:

intermolecular forces

What is the IMF that all substances/compounds have?

van der Waals Forces/London Dispersion

What type of IMFs can be present in non-polar molecules?

London Dispersion

Intramolecular forces:

Strong attractive forces between atoms in molecules

Intramolecular forces are also known as:

covalent bonds

Which is stronger, intermolecular forces or intramolecular forces?

intramolecular forces

What causes London Dispersion forces?

the Coulombic attractions between instantaneous dipoles of nonpolar molecules

How are instantaneous dipoles created in molecules?

Electrons can move in the molecule and by chance might be more concentrated in one direction

What does increasing mass and size of molecules do to IMFs?

makes them stronger

Larger molecules can form ___ instantaneous dipoles?

larger

Heavier molecules are more polarizable because:

the valence electrons are farther from the nucleus

Molecules with Larger Surface Area =

More Dispersion

Higher melting/boiling points =

Stronger Dispersion

What are dipole-dipole interactions?

attractive forces that act between polar molecules

The magnitude of dipole-dipole interactions depends on:

the magnitude of the dipole

As the dipole moment of the molecule increases, the boiling point:

also increases

Hydrogen bonding is a special type of:

dipole-dipole

The strongest kind of dipole-dipole interactions is:

hydrogen bonding

If a molecule is more electronegative:

it has a greater tendency to attract electrons towards itself when forming a chemical bond

Where is H-bonding found?

in molecules that contain H bonded to a small, highly electronegative atom such as N, O, or F

H-bonding forms a sort of ___ in solution?

network

Water molecules participate in:

multiple hydrogen bonding interactions with nearby water molecules

What does the high specific heat of water do?

it holds heat and prevents rapid temperature changes

What does the high heat of fusion of water mean?

it means that ice absorbs a lot of heat

What does the high heat of vaporization of water mean?

steam contains a lot of energy for work

Water also has high ___ and high ___?

surface tension and heat conductivity

What causes water to be able to flow between two things?

the low viscosity

Why is water known as the universal solvent?

because of the high polarity

Ice floats on water, meaning that:

ice is less dense than liquid water

What type of bonds connect the base pairs of DNA in different strands together?

h-bonding

Ions have a permanent, fixed:

charge

What kind of charges do dipoles have?

partial

What does the fixed charge of ions lead to?

stronger interactions

What happens to the strength of interactions when the ion charge is larger?

it increases

Ion-permanent Dipole Interactions are stronger at closer:

distnaces

Ion-permanent Dipole Interactions are stronger at higher:

ionic charge

Ion-permanent Dipole Interactions are stronger with larger:

dipole magnitude

What are ion-dipole interaction?

Coulombic attractions between ions (either positive or negative) and polar molecules

What are ion-ion interactions?

Coulombic attractions between positive and negative ions

Higher melting/boiling point =

stronger IMFs

Increasing molecular weight =

Higher Melting Point/ Boiling Point & IMFs

Increasing surface area =

Higher Melting Point/ Boiling Point & IMFs

Overall IMFs Strength:

Ionic > H - bonding > dipole/dipole > london dispersion

Why does water form a droplet shape in it drops?

because of surface tension

Why are molecules at the surface not happy?

this is because they want to be with their fellow molecules and surface tension want to minimize the amount of surface they have — (won't be able to experience the intermolecular forces of a neighbor)

What shape has the smallest surface area to volume?

spheres

What can soap do to the surface tension of water?

reduce it

What type of interactions is silica in a cylinder and water inside of it?

dipole-dipole interactions

What kind of bonds does glass have?

polar S-O bonds

What is capillary action?

the phenomenon where a liquid spontaneously rises in a narrow tube or porous material against gravity, driven by the forces of adhesion and cohesion, resulting in a visible rise of the liquid level within the tube or material

What is adhesion in capillary action?

attraction between the liquid and the container walls

What is cohesion in capillary action?

attraction between the liquid molecules themselves

What does the meniscus of polar water look like in a glass tube?

u shaped

What does the meniscus of non-polar mercury look like in a glass tube?

upside down u shaped

Viscosity =

resistance to flow

Enthalpy of fusion:

the amount of energy required to convert one mole of solid into liquid

Enthalpy of vaporization:

the amount of heat required to convert 1 gram of a liquid into vapor without a change in temperature

Vaporization:

when liquid is converted into a gas

In an open container, vaporization continues until:

all the liquid is converted into vapor

In a closed container, the process of vaporization is:

countered by the process of condensation

At equilibrium for vapor pressure:

The number of molecules in the gas phase or liquid phase stays constant does not change with time.

Vapor Pressure:

The pressure of a vapor in equilibrium with a liquid.

Vapor pressure is __ of the volume of the container?

independent

Does vapor pressure depend on the IMFs?

yes

As temp increases, vapor pressure:

also increases

As vapor pressure increases, boiling point:

decreases

In a Clausius-Clapeyron plot, the slope is proportional to:

ΔHvap

For the Clausius-Clapeyron equation, temperature should be in:

kelvin

If a solid has these following properties, what is it?
hard, brittle, conducts electricity as a liquid but not as a solid, high to very high melting points

ionic

If a solid has these following properties, what is it?
shiny, malleable, ductile, conducts heat and electricity well, variable hardness and melting temperature

metallic

If a solid has these following properties, what is it?
very hard, not conductive, very high melting points

covalent network

If a solid has these following properties, what is it?
variable hardness, variable brittleness, not conductive, low melting points

molecular

Unit Cell:

smallest repeating section of the lattice with the same symmetry as the extended lattice

A cubic cell has:

equal sides and square angles

In 3 dimensions, a unit cell can have:

7 basic forms

In a simple cubic lattice, the atoms are:

stacked directly on top of each other

A simple cubic lattice unit cell contains __ of an atom at each of it’s 8 corners, containing one atom total?

1/8

In the Body - Centered Cubic (BCC) lattice, a atom sits:

in the center of the unit cell

How many atoms does a BBC unit cell contain?

2 (one in middle & 1/8 at corners)

In the Face - Centered Cubic (FCC) lattice, atoms sit:

on the faces and corners of the unit cell

How many atoms does a FCC unit cell have?

4 (1/8 at 8 corners, and ½ at each of the 6 faces)

What is the coordination number of both Hexagonal Closest Packing and Cubic Closest Packing?

12 (3 above, 3 below, 6 in the plane)

What is a coordination number?

the number of nearest neighbor atoms that directly touch a central atom within a crystal lattice

In hexagonal closest packing:

the 3rd layer is in the same position as the 1st and the 4th layer is in the same position as the 2nd

In cubic closest packing:

the pattern is ABC packing

A liquid boils when:

vapor pressure is equal to or greater than the external pressure pushing on it

In simple ionic structures (no polyatomic ions) the anion is usually larger, and forms ___ lattice and the cation lattice forms another ___ lattice?

one; interpenetrating

The cations sit:

in the spaces between the anion lattice

Ionic solids tetrahedral hole =

where a cation is surrounded by 4 anions

Ionic solids octahedral hole =

where a cation is surrounded by 6 anions

Ionic solids cubic hole =

where a cation is surrounded by 8 anions

Solid to liquid =

melting

liquid to solid =

freezing

liquid to gas =

vaporization

gas to liquid =

condensation

solid to gas =

sublimation

gas to solid =

deposition

X - rays are used to determine:

the structure of crystalline solids

Crystallographic Defects substitutional impurity:

foreign atom takes the place of a regular atom at a lattice site