FORMULA SHEET
SOME BASIC CONCEPT OF
CHEMISTRY
THERMODYNAMICS
EQUILIBRIUM
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Basic Concepts of Chemistry — Formula Sheet
1. Atomic & Molecular Mass
Atomic mass unit (amu) = 1/12 mass of C-12 atom ≈ 1.66 × 10⁻²⁴ g
Molar mass (M) = mass of 1 mole of substance (g/mol)
2. Mole Concept
1 mole = 6.022 × 10²³ particles (Avogadro’s number, N_A)
Number of moles (n) = mass (m) / molar mass (M)
Number of particles = n × N_A
3. Concentration
Molarity (M) = moles of solute / liters of solution (mol/L)
Molality (m) = moles of solute / kg of solvent (mol/kg)
Mole fraction (X_i) = moles of component i / total moles
, 4. Gas Laws
Ideal Gas Equation: PV = nRT
where P = pressure (atm), V = volume (L), n = moles, R = 0.0821 L·atm/mol·K, T = temperature
(K)
Other forms:
Boyle’s Law: P₁V₁ = P₂V₂ (at constant T)
Charles’s Law: V₁/T₁ = V₂/T₂ (at constant P)
Avogadro’s Law: V ∝ n (at constant P & T)
5. Density of Gaρ = (PM) / (RT) where ρ = density (g/L), M = molar mass (g/mol)
--- Thermodynamics — Formula Sheet
1. First Law of Thermodynamics
ΔU = q + w
where ΔU = change in internal energy, q = heat added to system, w = work done on system
2. Work Done by Gas
w = -P_ext ΔV (for constant external pressure)
For expansion/compression: w = -∫P_ext dV
3. Enthalpy (H)
H = U + PV
ΔH = ΔU + PΔV (at constant pressure)
ΔH = q_p (heat at constant pressure)
SOME BASIC CONCEPT OF
CHEMISTRY
THERMODYNAMICS
EQUILIBRIUM
---
Basic Concepts of Chemistry — Formula Sheet
1. Atomic & Molecular Mass
Atomic mass unit (amu) = 1/12 mass of C-12 atom ≈ 1.66 × 10⁻²⁴ g
Molar mass (M) = mass of 1 mole of substance (g/mol)
2. Mole Concept
1 mole = 6.022 × 10²³ particles (Avogadro’s number, N_A)
Number of moles (n) = mass (m) / molar mass (M)
Number of particles = n × N_A
3. Concentration
Molarity (M) = moles of solute / liters of solution (mol/L)
Molality (m) = moles of solute / kg of solvent (mol/kg)
Mole fraction (X_i) = moles of component i / total moles
, 4. Gas Laws
Ideal Gas Equation: PV = nRT
where P = pressure (atm), V = volume (L), n = moles, R = 0.0821 L·atm/mol·K, T = temperature
(K)
Other forms:
Boyle’s Law: P₁V₁ = P₂V₂ (at constant T)
Charles’s Law: V₁/T₁ = V₂/T₂ (at constant P)
Avogadro’s Law: V ∝ n (at constant P & T)
5. Density of Gaρ = (PM) / (RT) where ρ = density (g/L), M = molar mass (g/mol)
--- Thermodynamics — Formula Sheet
1. First Law of Thermodynamics
ΔU = q + w
where ΔU = change in internal energy, q = heat added to system, w = work done on system
2. Work Done by Gas
w = -P_ext ΔV (for constant external pressure)
For expansion/compression: w = -∫P_ext dV
3. Enthalpy (H)
H = U + PV
ΔH = ΔU + PΔV (at constant pressure)
ΔH = q_p (heat at constant pressure)
