1. Chemistry formulae
Ideal Gas law
PV = nRT
n = number of moles P1V1 = P2V2
R = universal gas constant = 8.3145
T1 T2
J/mol K
Combined Gas law
Boyle's law
P1V1 = P2V2 V1 = V2
T1 T2
Charles law
Diffusion: Rate at which two gases mix
P1 = P2 Graham's law of diffusion
T1 T2
The rate of diffusion of a gas is inversely
Gay-Lussac law proportional to the square root of their
density or the molar mass of the gas.
Effusion: Rate at which a gas Solution: Solution is a homogeneous
escapes thru pin hole mixture of two or more substances.
Graham's law of effusion Solute is a substance that is dissolved in
The rate of effusion of a gas is the solution.
inversely proportional to the square Solvent is the substance that dissolves the
root of either the density or the molar solute. Solvent is present in greater
mass of the gas. amount.

2. Concentration is the ratio of solute Unit of Morality (M) : mol/L : moles per liter
and solvent. Unit of Morality (M) : mol/kg : moles per
Concentration can be measured using kg
morality, morality and mole fraction.
Morality (M) =
moles of solute
liters of
solution
Morality (m) = moles of
solute
kg of solution
Mole fraction: Mole fraction of a Dilution: Diluting a solution means adding
component in solution is the number of more solvent in solution without the addition
moles of that component divided by of more solute.
the total number of moles of all
components in the solution. MiVi = MfVf
Mi: Morality of solution before diluting.
Vi: Volume of solution before diluting.
Mf: Morality of solution after diluting.

3. molesa Vf: Volume of solution after diluting.
Mole-fraction (Xa)=
molesa + molesb ....
Mole: Mole is the amount of One mole of gas has volume of 22.4 liter
substance that contains same number at STP.
of particles as there are atoms in
Carbon-12. One mole of substance is
Avogadro's number (i.e. 6.023 x 1023).
Relation between moles and grams Ionization Enthalpy: It is the energy
1 mole = molecular weight of needed to remove an electron from an atom
substance in grams. or molecule (i.e from low state to n=∞). It is
always endothermic (i.e. positive).OR
Ionization energy: energy needed to remove
an electron from an atom
[A-]
pH = pKa + log10
[HA]
Henderson-Hasselbalch equation:
where
[A-]: Concentration of conjugate base
[HA]: concentration of the acid
OR
[Conjugate Base]
pH = pKa + log10
[Acid]

4. Ideal Gas Law
The ideal gas law is given by: PV = nRT
Where:
P: the absolute pressure of the gas
V: volume of the gas
n: number of moles, which is the ratio of mass and molar mass
R: universal gas constant, which is R = 8.3145 J · mol-1 · K-1
T: the absolute temperature
Henry's Law
Henry's law is given by: p = K · x
Where:p-partial pressure of the solute , H – Henry’s Constant
Hess' Law
Hess' Law can be expressed in 3 ways and they are:
For enthalpy we have:
For entropy we have:
For Gibbs' free energy we have:
Raoult's Law

5. Raoult's law is given by: Pi = xi - Pi *
Where: Pi pressure of component , xi – mole fraction in the solution , Pi * -
vapour
pressure of the pure substance. i.
In a solution with two liquids A and B, if no gas are present, the total vapor pressure is
given by:
Ptot = PA + PB
Where: PA – vapor pressure of liquid A , PB – vapor pressure of liquid B
For an ideal solution of liquids A and B, which obeys Raoult's law over the full range of
composition. The total pressure is given by:
ptot = xA pA* + xB pB* , where xA + xB = 1
Molar Enthalpy
Hm = H / n
Where: H: enthalpy; n: number of moles
Molar Mass
The molar mass equation is given by; M=Mr.g. mol-1
Where:
M: molar mass, which is the mass of one mole of a substance
Mr. Relative molar mass, also called molecular weight
This equation is obtained from the following equation:
Where:

6. NA: Avogadro Constant which is NA = 6.0221·1023mol-1
mu: molar mass constant, which is mu = 1 g · mol-1
Dilution
To calculate dilution, we can use the following formula: M1 * V1 = M2 * V2
Where:
M: Morality which is given by: M = n/NA which is given by: M = n/NA
V: Volume
Morality (M): Moles of Solute/Liters of solution
Unit of Morality (M): mol/L ; moles per liters
Moles of Solute/Liters of solution
Enthalpy
The enthalpy is given by the formula: H = U + pV
Where:
H: Enthalpy
U: Internal energy
p: pressure
V: volume
Gibbs ‘Free Energy
Gibbs’ free energy is given by: ΔG = ΔH- TΔS
Where:

7. H: Enthalpy
T: Temperature
S: entropy
Temperature Conversion
To convert between Kelvin and Celsius you can use the following formulas:
• From Kelvin to Celsius : °C= K - 273
• From Celsius to Kelvin: K = °C + 273