General Chemistry/Useful Equations

General

Density	$\frac{mass}{volume}$
Moles	$\frac{givenmass(g)}{gramformulamass}$
Percent Error	$\frac{measured-accepted}{accepted}\times 100\mathrm{\%}$
Percent Composition (by mass)	$\frac{massofpart}{massofwhole}\times 100\mathrm{\%}$
Molarity	$\frac{molesofsolute}{volumeofsolution}$
Molality	$\frac{molesofsolute}{massofsolventinkg}$
Rate of Reaction	$\frac{Differenceinquantity}{Differenceintime}$
de Broglie's law	$\lambda$ = $\frac{h}{mv}$

Atomic Structure

Symbol	Meaning	Symbol	Meaning
$E$	energy	$c$	speed of light
$v$	frequency	$\lambda$	wavelength
$Q$	charge	$r$	distance
$k_e$	Coulomb's constant	$h$	Plank's constant H/nkne

Energy of Wave	$E=hv$
Wave Relation	$c=\lambda v$
Coulomb's Law	$F_e=k_e\frac{Q_1{Q}_2}{r^2}$

Solutions, Liquids, and Gases

Symbol	Meaning
$P$	pressure
$V$	volume
$n$	number of moles
$T$	temperature (in Kelvin)
$K_f$	molal freezing point constant
$K_b$	molal boiling point constant
$\chi$	mole fraction
$m$	molality
$M$	molarity
$c$	specific heat capacity
$M_w$	mass of water (Kg)
$E_h$	heat energy released

Rauolt's Law	$P_{solution}=P_1{\chi }_1+P_2{\chi }_2+\dots$
Boiling Point Elevation	$\mathrm{\Delta }{T}_{solution}=K_b\cdot m_{solute}$
Freezing Point Depression	$\mathrm{\Delta }{T}_{solution}=K_f\cdot m_{solute}$
Ideal Gas Law	$PV=nRT$
Combined Gas Law	$\frac{P_1{V}_1}{n_1{T}_1}=\frac{P_2{V}_2}{n_2{T}_2}$
Titration	$M_A{V}_A=M_B{V}_B$
Dilution	$M_1{V}_1=M_2{V}_2$
Heat released by burning	$E_h=c{M}_w\mathrm{\Delta }T$

Equilibrium

Symbol	Meaning
$K_{eq}$	equilibrium constant (general)
$K_p$	pressure equilibrium constant
$K_c$	concentration equilibrium constant
$R$	gas law constant
$T$	temperature (in Kelvin)
$\mathrm{\Delta }n$	moles of product – moles of reactant

pH	$\mathrm{p}\mathrm{H}=-\log [{\mathrm{H}}^{\mathrm{+}}]$
pOH	$\mathrm{p}\mathrm{O}\mathrm{H}=-\log [\mathrm{O}{\mathrm{H}}^{\mathrm{-}}]$
(for water)	$\mathrm{p}\mathrm{H}+\mathrm{p}\mathrm{O}\mathrm{H}=14$
Pressure/Concentration	$K_p=K_c(RT{)}^{\mathrm{\Delta }n}$
Equilibrium, for a reaction $a\mathrm{A}+b\mathrm{B}\to c\mathrm{C}+d\mathrm{D}$	$K_{eq}=\frac{[\mathrm{C}{]}^c[\mathrm{D}{]}^d}{[\mathrm{A}{]}^a[\mathrm{B}{]}^b}$

Thermochemistry

Symbol	Meaning
$q$	heat energy
$m$	mass
$c$	specific heat
$T$	temperature (in Kelvin)
$S$	entropy
$H$	enthalpy
$G$	Gibbs free energy

Heat Transfer	$q=mc\mathrm{\Delta }T$
Enthalpy	$\mathrm{\Delta }H=H_{products}-H_{reactants}$
Entropy	$\mathrm{\Delta }S=S_{products}-S_{reactants}$
Free Energy	$\mathrm{\Delta }G=\mathrm{\Delta }H-T\mathrm{\Delta }S$