formulas

Density Formula

D = m/V

Mass from Density

m = D × V

Volume from Density

V = m/D

Percent Error

[(Experimental - Accepted) ÷ Accepted] × 100%

Kelvin Conversion

K = °C + 273.15

Celsius Conversion

°C = K - 273.15

Wave Equation

c = λν

Photon Energy Equation

E = hν

Speed of Light

c = 3.00 × 10⁸ m/s

Planck's Constant

h = 6.626 × 10⁻³⁴ J·s

Number of Neutrons

Mass Number - Atomic Number

Half-Life Equation

A = Ao(1/2)^(t/T)

Mole Conversion

1 mol = 6.022 × 10²³ particles

Molar Mass Conversion

1 mol = molar mass in grams

Percent Composition

(Mass of Element ÷ Mass of Compound) × 100%

Molarity Formula

M = mol/L

Moles from Molarity

mol = M × L

Volume from Molarity

L = mol/M

Dilution Formula

M₁V₁ = M₂V₂

Theoretical Yield Formula

Use stoichiometric mole ratios from a balanced equation

Percent Yield

(Actual Yield ÷ Theoretical Yield) × 100%

Specific Heat Formula

q = mcΔT

Heat Formula

q = mc(Tfinal - Tinitial)

Heat of Fusion

q = nΔHfus

Heat of Vaporization

q = nΔHvap

Thermochemical Heat Calculation

q = mol × ΔH

Hess's Law

ΔHoverall = ΣΔHsteps

Heat of Formation Equation

ΔHrxn = ΣnΔHf(products) - ΣnΔHf(reactants)

Boyle's Law

P₁V₁ = P₂V₂

Charles's Law

V₁/T₁ = V₂/T₂

Gay-Lussac's Law

P₁/T₁ = P₂/T₂

Combined Gas Law

P₁V₁/T₁ = P₂V₂/T₂

Avogadro's Law

V₁/n₁ = V₂/n₂

Ideal Gas Law

PV = nRT

Gas Constant (atm)

R = 0.0821 L·atm/mol·K

Gas Constant (Joules)

R = 8.314 J/mol·K

Moles from Ideal Gas Law

n = PV/RT

Volume from Ideal Gas Law

V = nRT/P

Pressure from Ideal Gas Law

P = nRT/V

Temperature from Ideal Gas Law

T = PV/nR

Dalton's Law of Partial Pressures

Ptotal = P₁ + P₂ + P₃ + …

Partial Pressure Formula

Pgas = Ptotal × Mole Fraction

Mole Fraction

χ = mol gas ÷ total mol

Graham's Law of Diffusion

Rate₁/Rate₂ = √(M₂/M₁)

Gas Density Formula

D = PM/RT

Gas Molar Mass Formula

M = dRT/P

STP Conditions

1 atm and 273 K

Molar Volume at STP

1 mol gas = 22.4 L

Particles to Moles

Particles ÷ 6.022 × 10²³

Moles to Particles

Moles × 6.022 × 10²³

Mass to Moles

Mass ÷ Molar Mass

Moles to Mass

Moles × Molar Mass

Limiting Reagent Process

Convert each reactant to moles of product; smallest amount wins

Empirical Formula Ratio

Divide all mole values by the smallest mole value

Molecular Formula Formula

n = Molecular Mass ÷ Empirical Formula Mass

Finding Molecular Formula

Empirical Formula × n

Reaction Heat from Stoichiometry

q = mol × ΔH from balanced equation

Electron Energy Change

ΔE = hf

Frequency Formula

ν = c/λ