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Chemistry formulas physics formulas
Chemistry formulas for grade 11, grade 12 and under graduates.
Ideal Gas law
PV = nRT
n = number of moles
R = universal gas constant = 8.3145 J/mol K

Combined Gas law
P1V1   =   P2V2
T1 T2

Boyle's law
P1V1 = P2V2

Charles law
V1   =   V2
T1 T2

Gay-Lussac law
P1   =   P2
T1 T2

Diffusion: Rate at which two gases mix
Graham's law of diffusion
The rate of diffusion of a gas is inversely proportional to the square root of their density or the molar mass of the gas.

Effusion: Rate at which a gas escapes thru pin hole
Graham's law of effusion
The rate of effusion of a gas is inversely proportional to the square root of either the density or the molar mass of the gas.

Solution: Solution is a homogeneous mixture of two or more substances.
Solute is a substance that is dissolved in the solution.
Solvent is the substance that dissolves the solute. Solvent is present in greater amount.

Concentration is the ratio of solute and solvent.
Concentration can be measured using molarity, molality and mole fraction.

Molarity (M) =   moles of solute
liters of solution

Molality (m) =   moles of solute
kg of solution

Unit of Molarity (M) : mol/L : moles per litre
Unit of Molality (M) : mol/kg : moles per kg

Mole fraction: Mole fraction of a component in solution is the number of moles of that component divided by the total number of moles of all components in the solution.
Mole-fraction (Xa)= molesa
molesa + molesb ....

Dilution: Siluting a solution means adding more solvent in solution without the addition of more solute.

MiVi = MfVf

Mi: Molarity of solution before diluting.
Vi: Volume of solution before diluting.
Mf: Molarity of solution after diluting.
Vf: Volume of solution after diluting.

Mole: Mole is the amount of substance that contains same number of particles as there are atoms in Carbon-12. One mole of substance is Avogadro's number (i.e. 6.023 x 1023).
One mole of gas has volume of 22.4 liter at STP.
Relation between moles and grams
1 mole = molecular weight of substance in grams.

Ionization Enthalpy: It is the energy needed to remove an electron from an atom or molecule (i.e from low state to n=∞). It is always endothermic (i.e. positive).


Ionization energy: energy needed to remove an electron from an atom

Henderson-Hasselbalch equation:
pH = pKa + log10  [A-]

[A-]: Concentration of conjugate base
[HA]: concentration of the acid

pH = pKa + log10  [Conjugate Base]