Formula Reference
Quick reference for common chemistry and physics formulas
Chemistry Formulas
Basic Chemistry
Moles
n = m / M
n = moles, m = mass (g), M = molar mass (g/mol)
Molarity
M = n / V
M = molarity (mol/L), n = moles, V = volume (L)
Dilution
M₁V₁ = M₂V₂
Before and after dilution
Percent Composition
% = (mass of element / total mass) × 100
Mass percentage of element in compound
Gas Laws
Ideal Gas Law
PV = nRT
P = pressure, V = volume, n = moles, R = 8.314 J/(mol⋅K), T = temperature (K)
Combined Gas Law
P₁V₁/T₁ = P₂V₂/T₂
Relates P, V, T for two states
Boyle's Law
P₁V₁ = P₂V₂
At constant temperature
Charles's Law
V₁/T₁ = V₂/T₂
At constant pressure
Thermochemistry
Heat Transfer
q = mcΔT
q = heat, m = mass, c = specific heat, ΔT = temp change
Enthalpy Change
ΔH = H(products) - H(reactants)
Energy change in reaction
Physics Formulas
Kinematics
Velocity
v = v₀ + at
Final velocity
Displacement
Δx = v₀t + ½at²
Position change with constant acceleration
Velocity-Displacement
v² = v₀² + 2aΔx
No time variable
Average Velocity
v̄ = Δx / Δt
Displacement over time
Dynamics
Newton's Second Law
F = ma
Force equals mass times acceleration
Weight
W = mg
Gravitational force
Friction
f = μN
μ = coefficient of friction, N = normal force
Momentum
p = mv
Linear momentum
Energy
Kinetic Energy
KE = ½mv²
Energy of motion
Potential Energy
PE = mgh
Gravitational potential energy
Work
W = Fd
Work done by constant force
Power
P = W/t
Rate of energy transfer
Waves
Wave Speed
v = fλ
v = speed, f = frequency, λ = wavelength
Period-Frequency
T = 1/f
T = period, f = frequency
Electricity
Ohm's Law
V = IR
V = voltage, I = current, R = resistance
Electric Power
P = IV
Power in electrical circuit
Resistors in Series
Rₜ = R₁ + R₂ + R₃...
Total resistance in series
Resistors in Parallel
1/Rₜ = 1/R₁ + 1/R₂...
Total resistance in parallel
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