Mole fraction of solute from molality (binary) (x_solute = m M_solvent / (1000 + m M_solvent) with m in mol/kg and M1 = molar mass of)

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x_solute = m M_solvent / (1000 + m M_solvent) with m in mol/kg and M1 = molar mass of solvent in g/mol

What each symbol means

SymbolWhat it stands for
mMolality (mol kg⁻¹)
M_1Molar mass of solvent (g mol⁻¹); for water M_1 = 18
x_2Mole fraction of solute (dimensionless)

When to use this

Binary solution; solvent is component 1; derived from n_2 = m kg_solvent and n_1 = 1000/M_1 per kg solvent.