chemistry gas equations

PV=nRTPV = nRT

ideal gas law

• Relates pressure (P), volume (V), moles (n), and temperature (T)

• Use when you need to solve for any one of these variables

• Works for most gas problems (especially when conditions change)

P1​V1​=P2​V2

Boyles Law

• When temperature and moles stay constant

• Shows inverse relationship between pressure and volume

• Example: compressing a gas → volume ↓, pressure ↑

P1/T1=P2/T2

gay lussac’s law

• When volume and moles stay constant

• Relates pressure and temperature

• Example: heating a sealed container → pressure increases

v1/T1 = v2/T2

Charles’s Law

• When pressure and moles stay constant

• Relates volume and temperature

• Example: balloon expands when heated

M=mRT/PV

Molar mass of a gas

• Find the molar mass (M) of an unknown gas

• You need mass (m), pressure, volume, and temperature

D=MP/RT

Density of a Gas

• Find the density (D) of a gas

• Useful when comparing gases or identifying unknowns

Ptot=ΣPn=P1+P2+P3+…P_{\text{tot}} = \Sigma P_n = P_1 + P_2 + P_3 +

Dalton’s partial law of pressures

• Find total pressure of a mixture of gases

• Add up all individual gas pressures

• Common in problems with collected gases over water