الكيمياء العامة/معادلات مفيدة

Density	${\frac {mass}{volume}}$
Moles	${\frac {given~mass~(g)}{gram~formula~mass}}$
Percent Error	${\frac {measured-accepted}{accepted}}\times 100\%$
Percent Composition (by mass)	${\frac {mass~of~part}{mass~of~whole}}\times 100\%$
Molarity	${\frac {moles~of~solute}{volume~of~solution}}$

الرمز	المعنى	الرمز	المعنى
$E$	energy	$c$	سرعة الضو
$f$	frequency	$\lambda$	الطول الموجي
$Q$	charge	$r$	المسافة
$k_{e}$	Coulomb's constant	$h$	ثابت بلانك

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

Rauolt's Law	$P_{solution}=P_{1}\chi _{1}+P_{2}\chi _{2}+\dots$
Boiling Point Elevation	$\Delta T_{solution}=K_{b}\cdot m_{solute}$
Freezing Point Depression	$\Delta T_{solution}=K_{f}\cdot m_{solute}$
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	$M_{1}V_{1}=M_{2}V_{2}$

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)
$\Delta n$	moles of product – moles of reactant

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

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