General Chemistry 2- Exam 1

Intermolecular forces, solutions and colligative properties

Fuerzas Intermoleculares

nonbonding forces that exist between molecules and they influence the physical properties of the substance.

melting

solid to liquid

vaporizing

liquid to gas

condensing

gas to liquid

freezing

liquid to solid

sublimacion

solid to gas

deposición

gas to solid

endothermic

a process where energy is absorbed by a system

exothermic

process where energy is liberated by a system

punto de embullicion

a mayor fuerzas

gas

conforms to shape and volume of container, has high compressibility and high ability to flow

liquid

conforms to shape and volume of container, but its limited by the surface, has very low compressibility and moderate ability to flow

solid

maintains its own shape and volume, almost none compressibility and almost none ability to flow

1,3,5

q=mcAt

2,4

q=nAH

Higher temperature

high vapor pressure

Low intermolecular forces

higher vapor pressure

vapor pressure

the pressure exerted by the vapor at equilibrium and its constant at a given temperature

boiling point

the temperature at which the vapor pressure equals the external pressure

melting point

temperature at which the solid and the liquid forms of a substance are a equilibrium

melting and freezing points

are the same

Polarity using molecular geometry

a molecule is polar if not all the bonds are cancelled by each other (the lone pairs dont matter)

3 types of bonding

ionic, covalent and metallic

ion dipole

Ion charge and dipole charge

dipole-dipole

T

hydrogen bonds

When an H molecule is attached to FON

dispersion

exist in all particles. except in cases involving small, polar molecules with large dipole molecules or those forming strong H bonds, **they are the dominant intermolecular force**

polarizability

increases down a group, decreases left to right

Cations

are less polarizable cause they are smaller

Anions

are more polarizable cause they are bigger

surface tension

energy required to increase the surface area a given amount

the stronger the intermolecular forces the higher it will be

raising temperature of a liquid reduces it

viscosity

resistance of a liquid to flow

the larger the intermolecular attractions, the larger it is

at high temperatures its low

solubility

depends on the attractive forces

like dissolves like

polar in polar, nonpolar in nonpolar

Water

great solvent

high specific heat capacity

high surface tension and capillarity

density differences in states

triple point

point where the three states meet each other

metalic solid

Intramolecular

Todo metal

Soft to hard, low to high mp, excellent thermal and electrical conductors, malleable

molecular solid

Intermoleculas

Dispersion, dipolo dipole y puente de hidrógeno

Se forman mayormente de compuestos covalentes y elementos no metales que su forms pura forman moléculas

Fairly soft, low to moderate mp, poor thermal and electrical conductors

ionic solid

Intramolecular

Todos los compuestos iónicos (cation y anion)

Hard and brittle, high mp, good thermal and electrical conductors when molten

Formados por un metal y un no metal

atomic solid

Intermoleculares

Dispersión o London

Solo gases nobles

Soft, very low mp, poor thermal and electrical conductors

Grupo 8A

solido red covalente

Intramoleculares

Metaloides y algunos óxidos, grupos binarios del grupo 3A y 5A. Very hard, very high mp, usually poor thermal and electrical conductors

Generalmente, grupos 3A, 4A, 5A y 6A, y metaloides

solute

dissolves in the solvent, its the lower quantity

solubility

the maximum amount that dissolves in a fixed quantity

solute (aggregated)+ heat

solute (separated) delta H> 0(+) - endothermic

solvent (aggregated) + heat

solvent (separated) delta H solvent > 0(+) - endothermic

solute (separated)+solvent (separated)

solution + heat, deltaHmix < 0(-) - exothermic

entropy

a thermodynamic quanitiy related to the number of ways the enrgy of a system can be dispersed through the motions of its particles

unsaturated solution

solution that contains less than the amount amount of dissolves solute

saturated solution

solution that contains the maximum amount of dissolved solute at given temperature in the presence of undissolved solute

supersaturated solution

solution that contains more than the equilibrium amount of dissolved solute

higher solubility

higher temperature

higher solubility (gases)

lower temperature

molarity

mol solute/ L of solution

molality

mol solute/ kg solvent

parts by mass

mass of solute/ mass of solution

mass percent

parts by mass x100

ppmil

parts by mass x1000

ppm

parts by mass x1000000

ppb

parts by mass x1000000000

parts by volume

volume of solute/ volume of solution

mole fraction

mol solute/ mol solute+ mol solvent