Mayer's Relation (Cp - Cv = R)

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Cp - Cv = R

What each symbol means

SymbolWhat it stands for
RUniversal gas constant = 8.314 J mol⁻¹ K⁻¹
CpMolar specific heat at constant pressure (J mol⁻¹ K⁻¹)
CvMolar specific heat at constant volume (J mol⁻¹ K⁻¹)

When to use this

Valid only for ideal gases. Per mole of ideal gas; for n moles: nCp - nCv = nR. Difference represents extra work done during expansion at constant pressure (PdV work = R per mole per degree).