Molality, also called molal concentration, is a measure of the concentration of a solute in a solution in terms of amount of substance in a specified amount of mass of the solvent. This contrasts with the definition of molarity which is based on a specified volume of solution.
![n_{solute}](/Images/godic/202501/27/4b757d9f64d40b20e00d5c4ca2e318c95858.png")
除以溶剂的质量![m_{solvent}](/Images/godic/202501/27/3c8853ac2de1d4612a657c32a1c4078e5858.png")
：![b = \frac{n_{solute}}{m_{solvent}}](/Images/godic/202501/27/fd64950cdeac83488b6bd327cf3774d45858.png")