The Mole and Stoichiometry
Number of moles (mass)
n = mass / molar mass Number of moles (volume)
n = volume / molar volume molar volume = 22.4 dm³ at s.t.p.
Number of moles (particles)
n = N / Nₐ Nₐ = 6.02 × 10²³
Concentration
c = n / V mol/dm³
Percentage composition
% element = (mass of element / molar mass) × 100 Gas Laws
Boyle’s law
P₁V₁ = P₂V₂ Charles’ law
V₁/T₁ = V₂/T₂ Pressure law
P₁/T₁ = P₂/T₂ General gas equation
P₁V₁/T₁ = P₂V₂/T₂ Ideal gas equation
PV = nRT Graham’s law of diffusion
r₁/r₂ = √(M₂/M₁) Acids, Bases and Electrochemistry
pH
pH = −log₁₀[H⁺] pOH
pOH = −log₁₀[OH⁻] pH + pOH
pH + pOH = 14 Titration (mole concept)
CₐVₐ/C_bV_b = nₐ/n_b n = mole ratio
Faraday’s first law
m = ZIt m = mass deposited, I = current, t = time
Thermochemistry
Heat change
q = mcΔT Enthalpy per mole
ΔH = q / n Gibbs free energy
ΔG = ΔH − TΔS Energy change of reaction
ΔH = ΣΔH(products) − ΣΔH(reactants) Test yourself on Chemistry
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