R - Gas Constant (SI units)

The Gas Constant, R, from the Ideal Gas Law is 8.31446261815324 Joules / (moles • Kelvin).  The gas constant (also known as the molar, universal, or ideal gas constant, denoted by the symbol R or R) is a physical constant which is featured in many fundamental equations in the physical sciences. The Gas Constant (R) is equivalent to the Boltzmann constant, but expressed in units of energy (i.e. the pressure-volume product) per temperature increment per mole (rather than energy per temperature increment per particle). The constant is also a combination of the constants from Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law.

The Gas Constant (R) appears in many formulas including the following:

• Ideal Gas Law: PV = nRT     (Click any Parameter)
  • P = n•R•T / V : Ideal Gas Law solved for pressure.
  • V = n•R•T / P : Ideal Gas Law solved for volume.
  • n = (P•V)/(R•T) : Ideal Gas Law solved for number of mole.
  • T = (P•V)/(n•R) : Ideal Gas Law solved for temperature.

• Activation Energy:  `E_a = (R*T_1*T_2)/(T_1 - T_2) ln(k_1/k_2)`

• Arrhenius Equation:  `k = Ae^(E_a/(RT))`

• Barometric Formula (Troposphere): `p = p_0*(1 - (L*h)/T_0)^((g*M)/(R*L))`

• Clausius-Clapeyron Equation:  `ln(P_2/P_1) = (DeltaH_(vap))/R * (1/T_1 - 1/T_2)`

• Compressibility Factor:  `Z = (p*V_m)/(R*T)`

• Peng-Robinson Equation of State:  `p = (R*T)/(V_m - b) - (a*alpha)/(V_m^2 + 2*b*V_m - b^2)`

• Reduced Specific Volume:  `v_r = v/(R* (T_cr)/P_c)`

• Van't Hoff Equation:  `ΔH^0 = R * ( -ln(K_2/K_1))/ (1/T_1 - 1/T_2)`

• Root-mean-square Speed: `V_(rms) =sqrt((3*R*T) / M)`

Chemistry Calculators

• R - Gas Constant: 8.3144626181532 J/(K⋅mol)
• Boyle's Law Calculator:  P₁ • V₁ = P₂ • V₂
• Charles Law Calculator: V₁• T₂ = V₂ • T₁
• Combined Gas Law Calculator:   P•V / T= k
• Gay-Lussac Law:  T₁•P₂ =T₂•P₁ 
• Ideal Gas Law: P•V = n•R•T
• Bragg's Law:   n·λ = 2d·sinθ
• Hess' Law:  ΔH⁰_rxn=ΔH⁰_a+ΔH⁰_b+ΔH⁰_c+ΔH⁰_d
• Internal Energy: ΔU = q + ω 
• Activation Energy:  E_a = (R*T₁⋅T₂)/(T₁ - T₂) ⋅  ln(k₁/k₂)
• Arrhenius Equation:  k = Ae^E_a/(RT)
• Clausius-Clapeyron Equation:  ln(P₂/P₁) = (ΔH_vap)/R * (1/T₁ - 1/T₂)
• Compressibility Factor: Z = (p*V_m)/(R*T)
• Peng-Robinson Equation of State:  p = (R*T)/(V_m - b) - (a*α)/(V_m² + 2*b*V_m - b²)
• Reduced Specific Volume:  v_r = v/(R* T_cr / P_c)
• Van't Hoff Equation:  ΔH⁰ = R * ( -ln(K₂/K₁))/ (1/T₁ - 1/T₂)

Reference

• Some descriptive text in the description of the Gas constant comes from Wikipedia:  wikipedia/wiki/Gas_constant