Chem 102 Exam 1

Boiling point , Higher IMF

Higher BP

Viscosity, Higher IMF

Higher viscosity

Surface Tension, Higher IMF

Higher surface tension

Vapor Pressure, Higher IMF

Lower vapor pressure

delta H

change in enthalpy or heat

delta S

change in entropy or disorder

Solid to liquid to gas

positive Delta H and S

gas to liquid to solid

negative delta H and S

Dela H Fusion

melting (solid to liquid)

Delta Hvap

heat of vaporization (liquid to gas)

delta H freezing

negative delta H fusion

delta H condensation

negative delta Hvap

delta G =

Delta H (enthalpy) - T(time) Delta S (entropy)

*g(l)=

C(specific heat) (mass) (change in temp)

g(l)=

C(molar heat capacity) (mols) (change in temp)

q=

Delta H x Moles

Clausius Clapeyron

Ln(p1/p2)=Delta Hvap/R (1/T2 - 1/T1), Temp in K, R=3.14

Crystalline solid

Lattice structure, rigid and long range order

Amorphous Solid

lack a regular three dimensional arrangement of atoms

Ionic Crystals

Metal + nonmetal, hard, high melting points, brittle

Covalent crystals

held together by covalent bonds, hard, high melting point, brittle

Molecular crystals

molecules held in a repeating pattern by IMF, low melting point, soft

Metallic crystals

metal atoms sharing a valence electron

Unit cell

basic repeating structural unit of a crystalline solid

Simple cubic

atom in each corner, coordination number 6,

Body centered face cubic

the spheres in each layer rest in the depression between the spheres in the previous layer, coordination # 8

Body centered cubic

atoms per cell: 2

Primitive cubic

atoms per cell: 1

Hexagonal closest packing

A, B pattern, coordination # 12

Cubic closest packing

A, B, C pattern, coordination # 12

face centered cubic

Atoms per unit cell: 4

Solvent + solvent

IMF forces present

Solute + solvent

New IMF forces being made

Solute + solute

Some IMFs are broken

Delta H solution =

delta H solvent-solvent + delta H solute-solute + delta H solute-solvent

Molarity (M)

mol solute/l of solution

Mole fraction (X)

mol of component/ total mols

Mass %

(mass solute/mass solution) x 100

parts per million (ppm)

(mass solute/mass solution) x 10^6

parts per billion (ppb)

(mass solute/mass solution) x 10^9

Molality (m)

mol solute/kg solvent

Solubility and temperature of solids in liquid

temp increases, solubility increases

Solubility of temperature of gas in liquids

temp increases, solubility decreases

Pressure of gas above liquid

directly proportional to solubility of gas in a liquid

Vapor pressure lowering equation

Psolution= Psolvent(pure)x Xsolvent(mole fraction)

Nonvolatile

has no vapor pressure

Volatile

has vapor pressure

Colligative properties depend on?

the number of dissolved particles

Boiling point elevation equation

delta Tb = Kb(boiling point constant) x m (molality), add value to boiling point of pure solute

Freezing point depression equation

delta Tf = -Kf(freezing point constant) x m (molality), subtract value from freezing point of pure solute

Osmotic pressure equation

=M(molarity)R(constant 0.08206)T(temp in K)

Equilibrium constant given partial pressure

C(equilibrium constant)= K(constant) P(pressure atm)

miscible

when two liquids form a homogenous mixture

Experimental equation for determining rate law

(ration of concentrations)^x = (ratio of initial rates), where x is the order with respect to that component

Rate equation

= K[A]^x[B]^x, where K is rate constant

Integrated rate law zero order

[A]t = -kt + [A]0, slope of [A]0/time

Integrated rate law first order

Ln[A]t = (-k)(t) + Ln[A]0, slope Ln[A]t/time

Integrated rate law second order

1/[A]t= kt + 1/[A]0

1st order half life equation

t1/2= Ln(2)/k

Reaction rate and temperature

more collisions, equals faster rate

Arrhenius Equation (Ea)

Ln(k2/k1)=( -Ea/R(8.314) )(1/T2- 1/T1) temp in k

elementary reactions

happens in one step

unimolecular

one reactant molecule

bimolecular

two reactant molecules

termolecular

three reactant molecules

Rate law for overall reaction

depends on the slowest step

reaction intermediate

1st seen as a product, used up later, not in overall reaction